Skip to content

L
linux
Commit c33e97ef authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Jonathan Corbet
Browse files
Options

docs: filesystems: convert proc.txt to ReST 

This document has a nice format! Unfortunately, not exactly
ReST. So, several adjustments were required:

- Add a SPDX header;
- Adjust document and section titles;
- Whitespace fixes and new line breaks;
- Mark literal blocks as such;
- Add table markups;
- Add table captions;
- Add it to filesystems/index.rst.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1d113d860188de416ca3b0b97371dc2195433d5b.1581955849.git.mchehab+huawei@kernel.orgSigned-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 18ccb223
Hide whitespace changes
Inline Side-by-side
Showing with 834 additions and 711 deletions
Documentation/filesystems/index.rst
View file @ c33e97ef
...@@ -81,5 +81,6 @@ Documentation for filesystem implementations. ...@@ -81,5 +81,6 @@ Documentation for filesystem implementations.
omfs omfs
orangefs orangefs
overlayfs overlayfs
proc
virtiofs virtiofs
vfat vfat
Documentation/filesystems/proc.txt → Documentation/filesystems/proc.rst
View file @ c33e97ef
------------------------------------------------------------------------------ .. SPDX-License-Identifier: GPL-2.0
T H E /proc F I L E S Y S T E M
------------------------------------------------------------------------------ ====================
/proc/sys Terrehon Bowden <terrehon@pacbell.net> October 7 1999 The /proc Filesystem
Bodo Bauer <bb@ricochet.net> ====================
===================== ======================================= ================
/proc/sys Terrehon Bowden <terrehon@pacbell.net>, October 7 1999
Bodo Bauer <bb@ricochet.net>
2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000
move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009
fixes/update part 1.1 Stefani Seibold <stefani@seibold.net> June 9 2009
===================== ======================================= ================
2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000
move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009
------------------------------------------------------------------------------
Version 1.3 Kernel version 2.2.12
Kernel version 2.4.0-test11-pre4
------------------------------------------------------------------------------
fixes/update part 1.1 Stefani Seibold <stefani@seibold.net> June 9 2009
Table of Contents .. Table of Contents
-----------------
0 Preface 0 Preface
0.1 Introduction/Credits 0.1 Introduction/Credits
...@@ -50,9 +51,8 @@ Table of Contents ...@@ -50,9 +51,8 @@ Table of Contents
4 Configuring procfs 4 Configuring procfs
4.1 Mount options 4.1 Mount options
------------------------------------------------------------------------------
Preface Preface
------------------------------------------------------------------------------ =======
0.1 Introduction/Credits 0.1 Introduction/Credits
------------------------ ------------------------
...@@ -95,20 +95,18 @@ We don't guarantee the correctness of this document, and if you come to us ...@@ -95,20 +95,18 @@ We don't guarantee the correctness of this document, and if you come to us
complaining about how you screwed up your system because of incorrect complaining about how you screwed up your system because of incorrect
documentation, we won't feel responsible... documentation, we won't feel responsible...
------------------------------------------------------------------------------ Chapter 1: Collecting System Information
CHAPTER 1: COLLECTING SYSTEM INFORMATION ========================================
------------------------------------------------------------------------------
------------------------------------------------------------------------------
In This Chapter In This Chapter
------------------------------------------------------------------------------ ---------------
* Investigating the properties of the pseudo file system /proc and its * Investigating the properties of the pseudo file system /proc and its
ability to provide information on the running Linux system ability to provide information on the running Linux system
* Examining /proc's structure * Examining /proc's structure
* Uncovering various information about the kernel and the processes running * Uncovering various information about the kernel and the processes running
on the system on the system
------------------------------------------------------------------------------
------------------------------------------------------------------------------
The proc file system acts as an interface to internal data structures in the The proc file system acts as an interface to internal data structures in the
kernel. It can be used to obtain information about the system and to change kernel. It can be used to obtain information about the system and to change
...@@ -134,9 +132,11 @@ never act on any new process that the kernel may, through chance, have ...@@ -134,9 +132,11 @@ never act on any new process that the kernel may, through chance, have
also assigned the process ID <pid>. Instead, operations on these FDs also assigned the process ID <pid>. Instead, operations on these FDs
usually fail with ESRCH. usually fail with ESRCH.
Table 1-1: Process specific entries in /proc .. table:: Table 1-1: Process specific entries in /proc
..............................................................................
============= ===============================================================
File Content File Content
============= ===============================================================
clear_refs Clears page referenced bits shown in smaps output clear_refs Clears page referenced bits shown in smaps output
cmdline Command line arguments cmdline Command line arguments
cpu Current and last cpu in which it was executed (2.4)(smp) cpu Current and last cpu in which it was executed (2.4)(smp)
...@@ -160,10 +160,10 @@ Table 1-1: Process specific entries in /proc ...@@ -160,10 +160,10 @@ Table 1-1: Process specific entries in /proc
can be derived from smaps, but is faster and more convenient can be derived from smaps, but is faster and more convenient
numa_maps An extension based on maps, showing the memory locality and numa_maps An extension based on maps, showing the memory locality and
binding policy as well as mem usage (in pages) of each mapping. binding policy as well as mem usage (in pages) of each mapping.
.............................................................................. ============= ===============================================================
For example, to get the status information of a process, all you have to do is For example, to get the status information of a process, all you have to do is
read the file /proc/PID/status: read the file /proc/PID/status::
>cat /proc/self/status >cat /proc/self/status
Name: cat Name: cat
...@@ -222,14 +222,17 @@ contains details information about the process itself. Its fields are ...@@ -222,14 +222,17 @@ contains details information about the process itself. Its fields are
explained in Table 1-4. explained in Table 1-4.
(for SMP CONFIG users) (for SMP CONFIG users)
For making accounting scalable, RSS related information are handled in an For making accounting scalable, RSS related information are handled in an
asynchronous manner and the value may not be very precise. To see a precise asynchronous manner and the value may not be very precise. To see a precise
snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table. snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
It's slow but very precise. It's slow but very precise.
Table 1-2: Contents of the status files (as of 4.19) .. table:: Table 1-2: Contents of the status files (as of 4.19)
..............................................................................
========================== ===================================================
Field Content Field Content
========================== ===================================================
Name filename of the executable Name filename of the executable
Umask file mode creation mask Umask file mode creation mask
State state (R is running, S is sleeping, D is sleeping State state (R is running, S is sleeping, D is sleeping
...@@ -254,7 +257,8 @@ Table 1-2: Contents of the status files (as of 4.19) ...@@ -254,7 +257,8 @@ Table 1-2: Contents of the status files (as of 4.19)
VmPin pinned memory size VmPin pinned memory size
VmHWM peak resident set size ("high water mark") VmHWM peak resident set size ("high water mark")
VmRSS size of memory portions. It contains the three VmRSS size of memory portions. It contains the three
following parts (VmRSS = RssAnon + RssFile + RssShmem) following parts
(VmRSS = RssAnon + RssFile + RssShmem)
RssAnon size of resident anonymous memory RssAnon size of resident anonymous memory
RssFile size of resident file mappings RssFile size of resident file mappings
RssShmem size of resident shmem memory (includes SysV shm, RssShmem size of resident shmem memory (includes SysV shm,
...@@ -292,27 +296,32 @@ Table 1-2: Contents of the status files (as of 4.19) ...@@ -292,27 +296,32 @@ Table 1-2: Contents of the status files (as of 4.19)
Mems_allowed_list Same as previous, but in "list format" Mems_allowed_list Same as previous, but in "list format"
voluntary_ctxt_switches number of voluntary context switches voluntary_ctxt_switches number of voluntary context switches
nonvoluntary_ctxt_switches number of non voluntary context switches nonvoluntary_ctxt_switches number of non voluntary context switches
.............................................................................. ========================== ===================================================
Table 1-3: Contents of the statm files (as of 2.6.8-rc3)
.............................................................................. .. table:: Table 1-3: Contents of the statm files (as of 2.6.8-rc3)
======== =============================== ==============================
Field Content Field Content
======== =============================== ==============================
size total program size (pages) (same as VmSize in status) size total program size (pages) (same as VmSize in status)
resident size of memory portions (pages) (same as VmRSS in status) resident size of memory portions (pages) (same as VmRSS in status)
shared number of pages that are shared (i.e. backed by a file, same shared number of pages that are shared (i.e. backed by a file, same
as RssFile+RssShmem in status) as RssFile+RssShmem in status)
trs number of pages that are 'code' (not including libs; broken, trs number of pages that are 'code' (not including libs; broken,
includes data segment) includes data segment)
lrs number of pages of library (always 0 on 2.6) lrs number of pages of library (always 0 on 2.6)
drs number of pages of data/stack (including libs; broken, drs number of pages of data/stack (including libs; broken,
includes library text) includes library text)
dt number of dirty pages (always 0 on 2.6) dt number of dirty pages (always 0 on 2.6)
.............................................................................. ======== =============================== ==============================
.. table:: Table 1-4: Contents of the stat files (as of 2.6.30-rc7)
Table 1-4: Contents of the stat files (as of 2.6.30-rc7) ============= ===============================================================
.............................................................................. Field Content
Field Content ============= ===============================================================
pid process id pid process id
tcomm filename of the executable tcomm filename of the executable
state state (R is running, S is sleeping, D is sleeping in an state state (R is running, S is sleeping, D is sleeping in an
...@@ -348,7 +357,8 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7) ...@@ -348,7 +357,8 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7)
blocked bitmap of blocked signals blocked bitmap of blocked signals
sigign bitmap of ignored signals sigign bitmap of ignored signals
sigcatch bitmap of caught signals sigcatch bitmap of caught signals
0 (place holder, used to be the wchan address, use /proc/PID/wchan instead) 0 (place holder, used to be the wchan address,
use /proc/PID/wchan instead)
0 (place holder) 0 (place holder)
0 (place holder) 0 (place holder)
exit_signal signal to send to parent thread on exit exit_signal signal to send to parent thread on exit
...@@ -365,39 +375,40 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7) ...@@ -365,39 +375,40 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7)
arg_end address below which program command line is placed arg_end address below which program command line is placed
env_start address above which program environment is placed env_start address above which program environment is placed
env_end address below which program environment is placed env_end address below which program environment is placed
exit_code the thread's exit_code in the form reported by the waitpid system call exit_code the thread's exit_code in the form reported by the waitpid
.............................................................................. system call
============= ===============================================================
The /proc/PID/maps file contains the currently mapped memory regions and The /proc/PID/maps file contains the currently mapped memory regions and
their access permissions. their access permissions.
The format is: The format is::
address perms offset dev inode pathname address perms offset dev inode pathname
08048000-08049000 r-xp 00000000 03:00 8312 /opt/test 08048000-08049000 r-xp 00000000 03:00 8312 /opt/test
08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
0804a000-0806b000 rw-p 00000000 00:00 0 [heap] 0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
a7cb1000-a7cb2000 ---p 00000000 00:00 0 a7cb1000-a7cb2000 ---p 00000000 00:00 0
a7cb2000-a7eb2000 rw-p 00000000 00:00 0 a7cb2000-a7eb2000 rw-p 00000000 00:00 0
a7eb2000-a7eb3000 ---p 00000000 00:00 0 a7eb2000-a7eb3000 ---p 00000000 00:00 0
a7eb3000-a7ed5000 rw-p 00000000 00:00 0 a7eb3000-a7ed5000 rw-p 00000000 00:00 0
a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6 a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6 a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6
a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6 a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6
a800b000-a800e000 rw-p 00000000 00:00 0 a800b000-a800e000 rw-p 00000000 00:00 0
a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0 a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0
a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0 a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0
a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0 a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0
a8024000-a8027000 rw-p 00000000 00:00 0 a8024000-a8027000 rw-p 00000000 00:00 0
a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2 a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2
a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2 a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2
a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2 a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2
aff35000-aff4a000 rw-p 00000000 00:00 0 [stack] aff35000-aff4a000 rw-p 00000000 00:00 0 [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso] ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
where "address" is the address space in the process that it occupies, "perms" where "address" is the address space in the process that it occupies, "perms"
is a set of permissions: is a set of permissions::
r = read r = read
w = write w = write
...@@ -411,42 +422,44 @@ with the memory region, as the case would be with BSS (uninitialized data). ...@@ -411,42 +422,44 @@ with the memory region, as the case would be with BSS (uninitialized data).
The "pathname" shows the name associated file for this mapping. If the mapping The "pathname" shows the name associated file for this mapping. If the mapping
is not associated with a file: is not associated with a file:
[heap] = the heap of the program ======= ====================================
[stack] = the stack of the main process [heap] the heap of the program
[vdso] = the "virtual dynamic shared object", [stack] the stack of the main process
[vdso] the "virtual dynamic shared object",
the kernel system call handler the kernel system call handler
======= ====================================
or if empty, the mapping is anonymous. or if empty, the mapping is anonymous.
The /proc/PID/smaps is an extension based on maps, showing the memory The /proc/PID/smaps is an extension based on maps, showing the memory
consumption for each of the process's mappings. For each mapping (aka Virtual consumption for each of the process's mappings. For each mapping (aka Virtual
Memory Area, or VMA) there is a series of lines such as the following: Memory Area, or VMA) there is a series of lines such as the following::
08048000-080bc000 r-xp 00000000 03:02 13130 /bin/bash 08048000-080bc000 r-xp 00000000 03:02 13130 /bin/bash
Size: 1084 kB Size: 1084 kB
KernelPageSize: 4 kB KernelPageSize: 4 kB
MMUPageSize: 4 kB MMUPageSize: 4 kB
Rss: 892 kB Rss: 892 kB
Pss: 374 kB Pss: 374 kB
Shared_Clean: 892 kB Shared_Clean: 892 kB
Shared_Dirty: 0 kB Shared_Dirty: 0 kB
Private_Clean: 0 kB Private_Clean: 0 kB
Private_Dirty: 0 kB Private_Dirty: 0 kB
Referenced: 892 kB Referenced: 892 kB
Anonymous: 0 kB Anonymous: 0 kB
LazyFree: 0 kB LazyFree: 0 kB
AnonHugePages: 0 kB AnonHugePages: 0 kB
ShmemPmdMapped: 0 kB ShmemPmdMapped: 0 kB
Shared_Hugetlb: 0 kB Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB Private_Hugetlb: 0 kB
Swap: 0 kB Swap: 0 kB
SwapPss: 0 kB SwapPss: 0 kB
KernelPageSize: 4 kB KernelPageSize: 4 kB
MMUPageSize: 4 kB MMUPageSize: 4 kB
Locked: 0 kB Locked: 0 kB
THPeligible: 0 THPeligible: 0
VmFlags: rd ex mr mw me dw VmFlags: rd ex mr mw me dw
The first of these lines shows the same information as is displayed for the The first of these lines shows the same information as is displayed for the
mapping in /proc/PID/maps. Following lines show the size of the mapping mapping in /proc/PID/maps. Following lines show the size of the mapping
...@@ -461,26 +474,35 @@ The "proportional set size" (PSS) of a process is the count of pages it has ...@@ -461,26 +474,35 @@ The "proportional set size" (PSS) of a process is the count of pages it has
in memory, where each page is divided by the number of processes sharing it. in memory, where each page is divided by the number of processes sharing it.
So if a process has 1000 pages all to itself, and 1000 shared with one other So if a process has 1000 pages all to itself, and 1000 shared with one other
process, its PSS will be 1500. process, its PSS will be 1500.
Note that even a page which is part of a MAP_SHARED mapping, but has only Note that even a page which is part of a MAP_SHARED mapping, but has only
a single pte mapped, i.e. is currently used by only one process, is accounted a single pte mapped, i.e. is currently used by only one process, is accounted
as private and not as shared. as private and not as shared.
"Referenced" indicates the amount of memory currently marked as referenced or "Referenced" indicates the amount of memory currently marked as referenced or
accessed. accessed.
"Anonymous" shows the amount of memory that does not belong to any file. Even "Anonymous" shows the amount of memory that does not belong to any file. Even
a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE
and a page is modified, the file page is replaced by a private anonymous copy. and a page is modified, the file page is replaced by a private anonymous copy.
"LazyFree" shows the amount of memory which is marked by madvise(MADV_FREE). "LazyFree" shows the amount of memory which is marked by madvise(MADV_FREE).
The memory isn't freed immediately with madvise(). It's freed in memory The memory isn't freed immediately with madvise(). It's freed in memory
pressure if the memory is clean. Please note that the printed value might pressure if the memory is clean. Please note that the printed value might
be lower than the real value due to optimizations used in the current be lower than the real value due to optimizations used in the current
implementation. If this is not desirable please file a bug report. implementation. If this is not desirable please file a bug report.
"AnonHugePages" shows the ammount of memory backed by transparent hugepage. "AnonHugePages" shows the ammount of memory backed by transparent hugepage.
"ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by "ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by
huge pages. huge pages.
"Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by "Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by
hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical
reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field. reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field.
"Swap" shows how much would-be-anonymous memory is also used, but out on swap. "Swap" shows how much would-be-anonymous memory is also used, but out on swap.
For shmem mappings, "Swap" includes also the size of the mapped (and not For shmem mappings, "Swap" includes also the size of the mapped (and not
replaced by copy-on-write) part of the underlying shmem object out on swap. replaced by copy-on-write) part of the underlying shmem object out on swap.
"SwapPss" shows proportional swap share of this mapping. Unlike "Swap", this "SwapPss" shows proportional swap share of this mapping. Unlike "Swap", this
...@@ -489,36 +511,39 @@ does not take into account swapped out page of underlying shmem objects. ...@@ -489,36 +511,39 @@ does not take into account swapped out page of underlying shmem objects.
"THPeligible" indicates whether the mapping is eligible for allocating THP "THPeligible" indicates whether the mapping is eligible for allocating THP
pages - 1 if true, 0 otherwise. It just shows the current status. pages - 1 if true, 0 otherwise. It just shows the current status.
"VmFlags" field deserves a separate description. This member represents the kernel "VmFlags" field deserves a separate description. This member represents the
flags associated with the particular virtual memory area in two letter encoded kernel flags associated with the particular virtual memory area in two letter
manner. The codes are the following: encoded manner. The codes are the following:
rd - readable
wr - writeable == =======================================
ex - executable rd readable
sh - shared wr writeable
mr - may read ex executable
mw - may write sh shared
me - may execute mr may read
ms - may share mw may write
gd - stack segment growns down me may execute
pf - pure PFN range ms may share
dw - disabled write to the mapped file gd stack segment growns down
lo - pages are locked in memory pf pure PFN range
io - memory mapped I/O area dw disabled write to the mapped file
sr - sequential read advise provided lo pages are locked in memory
rr - random read advise provided io memory mapped I/O area
dc - do not copy area on fork sr sequential read advise provided
de - do not expand area on remapping rr random read advise provided
ac - area is accountable dc do not copy area on fork
nr - swap space is not reserved for the area de do not expand area on remapping
ht - area uses huge tlb pages ac area is accountable
ar - architecture specific flag nr swap space is not reserved for the area
dd - do not include area into core dump ht area uses huge tlb pages
sd - soft-dirty flag ar architecture specific flag
mm - mixed map area dd do not include area into core dump
hg - huge page advise flag sd soft dirty flag
nh - no-huge page advise flag mm mixed map area
mg - mergable advise flag hg huge page advise flag
nh no huge page advise flag
mg mergable advise flag
== =======================================
Note that there is no guarantee that every flag and associated mnemonic will Note that there is no guarantee that every flag and associated mnemonic will
be present in all further kernel releases. Things get changed, the flags may be present in all further kernel releases. Things get changed, the flags may
...@@ -531,6 +556,7 @@ enabled. ...@@ -531,6 +556,7 @@ enabled.
Note: reading /proc/PID/maps or /proc/PID/smaps is inherently racy (consistent Note: reading /proc/PID/maps or /proc/PID/smaps is inherently racy (consistent
output can be achieved only in the single read call). output can be achieved only in the single read call).
This typically manifests when doing partial reads of these files while the This typically manifests when doing partial reads of these files while the
memory map is being modified. Despite the races, we do provide the following memory map is being modified. Despite the races, we do provide the following
guarantees: guarantees:
...@@ -544,9 +570,9 @@ The /proc/PID/smaps_rollup file includes the same fields as /proc/PID/smaps, ...@@ -544,9 +570,9 @@ The /proc/PID/smaps_rollup file includes the same fields as /proc/PID/smaps,
but their values are the sums of the corresponding values for all mappings of but their values are the sums of the corresponding values for all mappings of
the process. Additionally, it contains these fields: the process. Additionally, it contains these fields:
Pss_Anon - Pss_Anon
Pss_File - Pss_File
Pss_Shmem - Pss_Shmem
They represent the proportional shares of anonymous, file, and shmem pages, as They represent the proportional shares of anonymous, file, and shmem pages, as
described for smaps above. These fields are omitted in smaps since each described for smaps above. These fields are omitted in smaps since each
...@@ -558,20 +584,25 @@ The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG ...@@ -558,20 +584,25 @@ The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
bits on both physical and virtual pages associated with a process, and the bits on both physical and virtual pages associated with a process, and the
soft-dirty bit on pte (see Documentation/admin-guide/mm/soft-dirty.rst soft-dirty bit on pte (see Documentation/admin-guide/mm/soft-dirty.rst
for details). for details).
To clear the bits for all the pages associated with the process To clear the bits for all the pages associated with the process::
> echo 1 > /proc/PID/clear_refs > echo 1 > /proc/PID/clear_refs
To clear the bits for the anonymous pages associated with the process To clear the bits for the anonymous pages associated with the process::
> echo 2 > /proc/PID/clear_refs > echo 2 > /proc/PID/clear_refs
To clear the bits for the file mapped pages associated with the process To clear the bits for the file mapped pages associated with the process::
> echo 3 > /proc/PID/clear_refs > echo 3 > /proc/PID/clear_refs
To clear the soft-dirty bit To clear the soft-dirty bit::
> echo 4 > /proc/PID/clear_refs > echo 4 > /proc/PID/clear_refs
To reset the peak resident set size ("high water mark") to the process's To reset the peak resident set size ("high water mark") to the process's
current value: current value::
> echo 5 > /proc/PID/clear_refs > echo 5 > /proc/PID/clear_refs
Any other value written to /proc/PID/clear_refs will have no effect. Any other value written to /proc/PID/clear_refs will have no effect.
...@@ -584,30 +615,33 @@ Documentation/admin-guide/mm/pagemap.rst. ...@@ -584,30 +615,33 @@ Documentation/admin-guide/mm/pagemap.rst.
The /proc/pid/numa_maps is an extension based on maps, showing the memory The /proc/pid/numa_maps is an extension based on maps, showing the memory
locality and binding policy, as well as the memory usage (in pages) of locality and binding policy, as well as the memory usage (in pages) of
each mapping. The output follows a general format where mapping details get each mapping. The output follows a general format where mapping details get
summarized separated by blank spaces, one mapping per each file line: summarized separated by blank spaces, one mapping per each file line::
address policy mapping details address policy mapping details
00400000 default file=/usr/local/bin/app mapped=1 active=0 N3=1 kernelpagesize_kB=4 00400000 default file=/usr/local/bin/app mapped=1 active=0 N3=1 kernelpagesize_kB=4
00600000 default file=/usr/local/bin/app anon=1 dirty=1 N3=1 kernelpagesize_kB=4 00600000 default file=/usr/local/bin/app anon=1 dirty=1 N3=1 kernelpagesize_kB=4
3206000000 default file=/lib64/ld-2.12.so mapped=26 mapmax=6 N0=24 N3=2 kernelpagesize_kB=4 3206000000 default file=/lib64/ld-2.12.so mapped=26 mapmax=6 N0=24 N3=2 kernelpagesize_kB=4
320621f000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 320621f000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
3206220000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 3206220000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
3206221000 default anon=1 dirty=1 N3=1 kernelpagesize_kB=4 3206221000 default anon=1 dirty=1 N3=1 kernelpagesize_kB=4
3206800000 default file=/lib64/libc-2.12.so mapped=59 mapmax=21 active=55 N0=41 N3=18 kernelpagesize_kB=4 3206800000 default file=/lib64/libc-2.12.so mapped=59 mapmax=21 active=55 N0=41 N3=18 kernelpagesize_kB=4
320698b000 default file=/lib64/libc-2.12.so 320698b000 default file=/lib64/libc-2.12.so
3206b8a000 default file=/lib64/libc-2.12.so anon=2 dirty=2 N3=2 kernelpagesize_kB=4 3206b8a000 default file=/lib64/libc-2.12.so anon=2 dirty=2 N3=2 kernelpagesize_kB=4
3206b8e000 default file=/lib64/libc-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 3206b8e000 default file=/lib64/libc-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
3206b8f000 default anon=3 dirty=3 active=1 N3=3 kernelpagesize_kB=4 3206b8f000 default anon=3 dirty=3 active=1 N3=3 kernelpagesize_kB=4
7f4dc10a2000 default anon=3 dirty=3 N3=3 kernelpagesize_kB=4 7f4dc10a2000 default anon=3 dirty=3 N3=3 kernelpagesize_kB=4
7f4dc10b4000 default anon=2 dirty=2 active=1 N3=2 kernelpagesize_kB=4 7f4dc10b4000 default anon=2 dirty=2 active=1 N3=2 kernelpagesize_kB=4
7f4dc1200000 default file=/anon_hugepage\040(deleted) huge anon=1 dirty=1 N3=1 kernelpagesize_kB=2048 7f4dc1200000 default file=/anon_hugepage\040(deleted) huge anon=1 dirty=1 N3=1 kernelpagesize_kB=2048
7fff335f0000 default stack anon=3 dirty=3 N3=3 kernelpagesize_kB=4 7fff335f0000 default stack anon=3 dirty=3 N3=3 kernelpagesize_kB=4
7fff3369d000 default mapped=1 mapmax=35 active=0 N3=1 kernelpagesize_kB=4 7fff3369d000 default mapped=1 mapmax=35 active=0 N3=1 kernelpagesize_kB=4
Where: Where:
"address" is the starting address for the mapping; "address" is the starting address for the mapping;
"policy" reports the NUMA memory policy set for the mapping (see Documentation/admin-guide/mm/numa_memory_policy.rst); "policy" reports the NUMA memory policy set for the mapping (see Documentation/admin-guide/mm/numa_memory_policy.rst);
"mapping details" summarizes mapping data such as mapping type, page usage counters, "mapping details" summarizes mapping data such as mapping type, page usage counters,
node locality page counters (N0 == node0, N1 == node1, ...) and the kernel page node locality page counters (N0 == node0, N1 == node1, ...) and the kernel page
size, in KB, that is backing the mapping up. size, in KB, that is backing the mapping up.
...@@ -621,81 +655,83 @@ the running kernel. The files used to obtain this information are contained in ...@@ -621,81 +655,83 @@ the running kernel. The files used to obtain this information are contained in
system. It depends on the kernel configuration and the loaded modules, which system. It depends on the kernel configuration and the loaded modules, which
files are there, and which are missing. files are there, and which are missing.
Table 1-5: Kernel info in /proc .. table:: Table 1-5: Kernel info in /proc
..............................................................................
File Content ============ ===============================================================
apm Advanced power management info File Content
buddyinfo Kernel memory allocator information (see text) (2.5) ============ ===============================================================
bus Directory containing bus specific information apm Advanced power management info
cmdline Kernel command line buddyinfo Kernel memory allocator information (see text) (2.5)
cpuinfo Info about the CPU bus Directory containing bus specific information
devices Available devices (block and character) cmdline Kernel command line
dma Used DMS channels cpuinfo Info about the CPU
filesystems Supported filesystems devices Available devices (block and character)
driver Various drivers grouped here, currently rtc (2.4) dma Used DMS channels
execdomains Execdomains, related to security (2.4) filesystems Supported filesystems
fb Frame Buffer devices (2.4) driver Various drivers grouped here, currently rtc (2.4)
fs File system parameters, currently nfs/exports (2.4) execdomains Execdomains, related to security (2.4)
ide Directory containing info about the IDE subsystem fb Frame Buffer devices (2.4)
interrupts Interrupt usage fs File system parameters, currently nfs/exports (2.4)
iomem Memory map (2.4) ide Directory containing info about the IDE subsystem
ioports I/O port usage interrupts Interrupt usage
irq Masks for irq to cpu affinity (2.4)(smp?) iomem Memory map (2.4)
isapnp ISA PnP (Plug&Play) Info (2.4) ioports I/O port usage
kcore Kernel core image (can be ELF or A.OUT(deprecated in 2.4)) irq Masks for irq to cpu affinity (2.4)(smp?)
kmsg Kernel messages isapnp ISA PnP (Plug&Play) Info (2.4)
ksyms Kernel symbol table kcore Kernel core image (can be ELF or A.OUT(deprecated in 2.4))
loadavg Load average of last 1, 5 & 15 minutes kmsg Kernel messages
locks Kernel locks ksyms Kernel symbol table
meminfo Memory info loadavg Load average of last 1, 5 & 15 minutes
misc Miscellaneous locks Kernel locks
modules List of loaded modules meminfo Memory info
mounts Mounted filesystems misc Miscellaneous
net Networking info (see text) modules List of loaded modules
mounts Mounted filesystems
net Networking info (see text)
pagetypeinfo Additional page allocator information (see text) (2.5) pagetypeinfo Additional page allocator information (see text) (2.5)
partitions Table of partitions known to the system partitions Table of partitions known to the system
pci Deprecated info of PCI bus (new way -> /proc/bus/pci/, pci Deprecated info of PCI bus (new way -> /proc/bus/pci/,
decoupled by lspci (2.4) decoupled by lspci (2.4)
rtc Real time clock rtc Real time clock
scsi SCSI info (see text) scsi SCSI info (see text)
slabinfo Slab pool info slabinfo Slab pool info
softirqs softirq usage softirqs softirq usage
stat Overall statistics stat Overall statistics
swaps Swap space utilization swaps Swap space utilization
sys See chapter 2 sys See chapter 2
sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4) sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4)
tty Info of tty drivers tty Info of tty drivers
uptime Wall clock since boot, combined idle time of all cpus uptime Wall clock since boot, combined idle time of all cpus
version Kernel version version Kernel version
video bttv info of video resources (2.4) video bttv info of video resources (2.4)
vmallocinfo Show vmalloced areas vmallocinfo Show vmalloced areas
.............................................................................. ============ ===============================================================
You can, for example, check which interrupts are currently in use and what You can, for example, check which interrupts are currently in use and what
they are used for by looking in the file /proc/interrupts: they are used for by looking in the file /proc/interrupts::
> cat /proc/interrupts > cat /proc/interrupts
CPU0 CPU0
0: 8728810 XT-PIC timer 0: 8728810 XT-PIC timer
1: 895 XT-PIC keyboard 1: 895 XT-PIC keyboard
2: 0 XT-PIC cascade 2: 0 XT-PIC cascade
3: 531695 XT-PIC aha152x 3: 531695 XT-PIC aha152x
4: 2014133 XT-PIC serial 4: 2014133 XT-PIC serial
5: 44401 XT-PIC pcnet_cs 5: 44401 XT-PIC pcnet_cs
8: 2 XT-PIC rtc 8: 2 XT-PIC rtc
11: 8 XT-PIC i82365 11: 8 XT-PIC i82365
12: 182918 XT-PIC PS/2 Mouse 12: 182918 XT-PIC PS/2 Mouse
13: 1 XT-PIC fpu 13: 1 XT-PIC fpu
14: 1232265 XT-PIC ide0 14: 1232265 XT-PIC ide0
15: 7 XT-PIC ide1 15: 7 XT-PIC ide1
NMI: 0 NMI: 0
In 2.4.* a couple of lines where added to this file LOC & ERR (this time is the In 2.4.* a couple of lines where added to this file LOC & ERR (this time is the
output of a SMP machine): output of a SMP machine)::
> cat /proc/interrupts > cat /proc/interrupts
CPU0 CPU1 CPU0 CPU1
0: 1243498 1214548 IO-APIC-edge timer 0: 1243498 1214548 IO-APIC-edge timer
1: 8949 8958 IO-APIC-edge keyboard 1: 8949 8958 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade 2: 0 0 XT-PIC cascade
...@@ -708,8 +744,8 @@ output of a SMP machine): ...@@ -708,8 +744,8 @@ output of a SMP machine):
15: 2183 2415 IO-APIC-edge ide1 15: 2183 2415 IO-APIC-edge ide1
17: 30564 30414 IO-APIC-level eth0 17: 30564 30414 IO-APIC-level eth0
18: 177 164 IO-APIC-level bttv 18: 177 164 IO-APIC-level bttv
NMI: 2457961 2457959 NMI: 2457961 2457959
LOC: 2457882 2457881 LOC: 2457882 2457881
ERR: 2155 ERR: 2155
NMI is incremented in this case because every timer interrupt generates a NMI NMI is incremented in this case because every timer interrupt generates a NMI
...@@ -726,21 +762,25 @@ In 2.6.2* /proc/interrupts was expanded again. This time the goal was for ...@@ -726,21 +762,25 @@ In 2.6.2* /proc/interrupts was expanded again. This time the goal was for
/proc/interrupts to display every IRQ vector in use by the system, not /proc/interrupts to display every IRQ vector in use by the system, not
just those considered 'most important'. The new vectors are: just those considered 'most important'. The new vectors are:
THR -- interrupt raised when a machine check threshold counter THR
interrupt raised when a machine check threshold counter
(typically counting ECC corrected errors of memory or cache) exceeds (typically counting ECC corrected errors of memory or cache) exceeds
a configurable threshold. Only available on some systems. a configurable threshold. Only available on some systems.
TRM -- a thermal event interrupt occurs when a temperature threshold TRM
a thermal event interrupt occurs when a temperature threshold
has been exceeded for the CPU. This interrupt may also be generated has been exceeded for the CPU. This interrupt may also be generated
when the temperature drops back to normal. when the temperature drops back to normal.
SPU -- a spurious interrupt is some interrupt that was raised then lowered SPU
a spurious interrupt is some interrupt that was raised then lowered
by some IO device before it could be fully processed by the APIC. Hence by some IO device before it could be fully processed by the APIC. Hence
the APIC sees the interrupt but does not know what device it came from. the APIC sees the interrupt but does not know what device it came from.
For this case the APIC will generate the interrupt with a IRQ vector For this case the APIC will generate the interrupt with a IRQ vector
of 0xff. This might also be generated by chipset bugs. of 0xff. This might also be generated by chipset bugs.
RES, CAL, TLB -- rescheduling, call and TLB flush interrupts are RES, CAL, TLB]
rescheduling, call and TLB flush interrupts are
sent from one CPU to another per the needs of the OS. Typically, sent from one CPU to another per the needs of the OS. Typically,
their statistics are used by kernel developers and interested users to their statistics are used by kernel developers and interested users to
determine the occurrence of interrupts of the given type. determine the occurrence of interrupts of the given type.
...@@ -756,7 +796,8 @@ IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the ...@@ -756,7 +796,8 @@ IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the
irq subdir is one subdir for each IRQ, and two files; default_smp_affinity and irq subdir is one subdir for each IRQ, and two files; default_smp_affinity and
prof_cpu_mask. prof_cpu_mask.
For example For example::
> ls /proc/irq/ > ls /proc/irq/
0 10 12 14 16 18 2 4 6 8 prof_cpu_mask 0 10 12 14 16 18 2 4 6 8 prof_cpu_mask
1 11 13 15 17 19 3 5 7 9 default_smp_affinity 1 11 13 15 17 19 3 5 7 9 default_smp_affinity
...@@ -764,20 +805,20 @@ For example ...@@ -764,20 +805,20 @@ For example
smp_affinity smp_affinity
smp_affinity is a bitmask, in which you can specify which CPUs can handle the smp_affinity is a bitmask, in which you can specify which CPUs can handle the
IRQ, you can set it by doing: IRQ, you can set it by doing::
> echo 1 > /proc/irq/10/smp_affinity > echo 1 > /proc/irq/10/smp_affinity
This means that only the first CPU will handle the IRQ, but you can also echo This means that only the first CPU will handle the IRQ, but you can also echo
5 which means that only the first and third CPU can handle the IRQ. 5 which means that only the first and third CPU can handle the IRQ.
The contents of each smp_affinity file is the same by default: The contents of each smp_affinity file is the same by default::
> cat /proc/irq/0/smp_affinity > cat /proc/irq/0/smp_affinity
ffffffff ffffffff
There is an alternate interface, smp_affinity_list which allows specifying There is an alternate interface, smp_affinity_list which allows specifying
a cpu range instead of a bitmask: a cpu range instead of a bitmask::
> cat /proc/irq/0/smp_affinity_list > cat /proc/irq/0/smp_affinity_list
1024-1031 1024-1031
...@@ -810,46 +851,46 @@ Linux uses slab pools for memory management above page level in version 2.2. ...@@ -810,46 +851,46 @@ Linux uses slab pools for memory management above page level in version 2.2.
Commonly used objects have their own slab pool (such as network buffers, Commonly used objects have their own slab pool (such as network buffers,
directory cache, and so on). directory cache, and so on).
.............................................................................. ::
> cat /proc/buddyinfo > cat /proc/buddyinfo
Node 0, zone DMA 0 4 5 4 4 3 ... Node 0, zone DMA 0 4 5 4 4 3 ...
Node 0, zone Normal 1 0 0 1 101 8 ... Node 0, zone Normal 1 0 0 1 101 8 ...
Node 0, zone HighMem 2 0 0 1 1 0 ... Node 0, zone HighMem 2 0 0 1 1 0 ...
External fragmentation is a problem under some workloads, and buddyinfo is a External fragmentation is a problem under some workloads, and buddyinfo is a
useful tool for helping diagnose these problems. Buddyinfo will give you a useful tool for helping diagnose these problems. Buddyinfo will give you a
clue as to how big an area you can safely allocate, or why a previous clue as to how big an area you can safely allocate, or why a previous
allocation failed. allocation failed.
Each column represents the number of pages of a certain order which are Each column represents the number of pages of a certain order which are
available. In this case, there are 0 chunks of 2^0*PAGE_SIZE available in available. In this case, there are 0 chunks of 2^0*PAGE_SIZE available in
ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE
available in ZONE_NORMAL, etc... available in ZONE_NORMAL, etc...
More information relevant to external fragmentation can be found in More information relevant to external fragmentation can be found in
pagetypeinfo. pagetypeinfo::
> cat /proc/pagetypeinfo > cat /proc/pagetypeinfo
Page block order: 9 Page block order: 9
Pages per block: 512 Pages per block: 512
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 0 0 0 1 1 1 1 1 1 1 0 Node 0, zone DMA, type Unmovable 0 0 0 1 1 1 1 1 1 1 0
Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Movable 1 1 2 1 2 1 1 0 1 0 2 Node 0, zone DMA, type Movable 1 1 2 1 2 1 1 0 1 0 2
Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 1 0 Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 1 0
Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Unmovable 103 54 77 1 1 1 11 8 7 1 9 Node 0, zone DMA32, type Unmovable 103 54 77 1 1 1 11 8 7 1 9
Node 0, zone DMA32, type Reclaimable 0 0 2 1 0 0 0 0 1 0 0 Node 0, zone DMA32, type Reclaimable 0 0 2 1 0 0 0 0 1 0 0
Node 0, zone DMA32, type Movable 169 152 113 91 77 54 39 13 6 1 452 Node 0, zone DMA32, type Movable 169 152 113 91 77 54 39 13 6 1 452
Node 0, zone DMA32, type Reserve 1 2 2 2 2 0 1 1 1 1 0 Node 0, zone DMA32, type Reserve 1 2 2 2 2 0 1 1 1 1 0
Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Number of blocks type Unmovable Reclaimable Movable Reserve Isolate Number of blocks type Unmovable Reclaimable Movable Reserve Isolate
Node 0, zone DMA 2 0 5 1 0 Node 0, zone DMA 2 0 5 1 0
Node 0, zone DMA32 41 6 967 2 0 Node 0, zone DMA32 41 6 967 2 0
Fragmentation avoidance in the kernel works by grouping pages of different Fragmentation avoidance in the kernel works by grouping pages of different
migrate types into the same contiguous regions of memory called page blocks. migrate types into the same contiguous regions of memory called page blocks.
...@@ -870,59 +911,63 @@ unless memory has been mlock()'d. Some of the Reclaimable blocks should ...@@ -870,59 +911,63 @@ unless memory has been mlock()'d. Some of the Reclaimable blocks should
also be allocatable although a lot of filesystem metadata may have to be also be allocatable although a lot of filesystem metadata may have to be
reclaimed to achieve this. reclaimed to achieve this.
..............................................................................
meminfo: meminfo
~~~~~~~
Provides information about distribution and utilization of memory. This Provides information about distribution and utilization of memory. This
varies by architecture and compile options. The following is from a varies by architecture and compile options. The following is from a
16GB PIII, which has highmem enabled. You may not have all of these fields. 16GB PIII, which has highmem enabled. You may not have all of these fields.
> cat /proc/meminfo ::
MemTotal: 16344972 kB > cat /proc/meminfo
MemFree: 13634064 kB
MemAvailable: 14836172 kB MemTotal: 16344972 kB
Buffers: 3656 kB MemFree: 13634064 kB
Cached: 1195708 kB MemAvailable: 14836172 kB
SwapCached: 0 kB Buffers: 3656 kB
Active: 891636 kB Cached: 1195708 kB
Inactive: 1077224 kB SwapCached: 0 kB
HighTotal: 15597528 kB Active: 891636 kB
HighFree: 13629632 kB Inactive: 1077224 kB
LowTotal: 747444 kB HighTotal: 15597528 kB
LowFree: 4432 kB HighFree: 13629632 kB
SwapTotal: 0 kB LowTotal: 747444 kB
SwapFree: 0 kB LowFree: 4432 kB
Dirty: 968 kB SwapTotal: 0 kB
Writeback: 0 kB SwapFree: 0 kB
AnonPages: 861800 kB Dirty: 968 kB
Mapped: 280372 kB Writeback: 0 kB
Shmem: 644 kB AnonPages: 861800 kB
KReclaimable: 168048 kB Mapped: 280372 kB
Slab: 284364 kB Shmem: 644 kB
SReclaimable: 159856 kB KReclaimable: 168048 kB
SUnreclaim: 124508 kB Slab: 284364 kB
PageTables: 24448 kB SReclaimable: 159856 kB
NFS_Unstable: 0 kB SUnreclaim: 124508 kB
Bounce: 0 kB PageTables: 24448 kB
WritebackTmp: 0 kB NFS_Unstable: 0 kB
CommitLimit: 7669796 kB Bounce: 0 kB
Committed_AS: 100056 kB WritebackTmp: 0 kB
VmallocTotal: 112216 kB CommitLimit: 7669796 kB
VmallocUsed: 428 kB Committed_AS: 100056 kB
VmallocChunk: 111088 kB VmallocTotal: 112216 kB
Percpu: 62080 kB VmallocUsed: 428 kB
HardwareCorrupted: 0 kB VmallocChunk: 111088 kB
AnonHugePages: 49152 kB Percpu: 62080 kB
ShmemHugePages: 0 kB HardwareCorrupted: 0 kB
ShmemPmdMapped: 0 kB AnonHugePages: 49152 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
MemTotal: Total usable ram (i.e. physical ram minus a few reserved
MemTotal
Total usable ram (i.e. physical ram minus a few reserved
bits and the kernel binary code) bits and the kernel binary code)
MemFree: The sum of LowFree+HighFree MemFree
MemAvailable: An estimate of how much memory is available for starting new The sum of LowFree+HighFree
MemAvailable
An estimate of how much memory is available for starting new
applications, without swapping. Calculated from MemFree, applications, without swapping. Calculated from MemFree,
SReclaimable, the size of the file LRU lists, and the low SReclaimable, the size of the file LRU lists, and the low
watermarks in each zone. watermarks in each zone.
...@@ -930,69 +975,99 @@ MemAvailable: An estimate of how much memory is available for starting new ...@@ -930,69 +975,99 @@ MemAvailable: An estimate of how much memory is available for starting new
page cache to function well, and that not all reclaimable page cache to function well, and that not all reclaimable
slab will be reclaimable, due to items being in use. The slab will be reclaimable, due to items being in use. The
impact of those factors will vary from system to system. impact of those factors will vary from system to system.
Buffers: Relatively temporary storage for raw disk blocks Buffers
Relatively temporary storage for raw disk blocks
shouldn't get tremendously large (20MB or so) shouldn't get tremendously large (20MB or so)
Cached: in-memory cache for files read from the disk (the Cached
in-memory cache for files read from the disk (the
pagecache). Doesn't include SwapCached pagecache). Doesn't include SwapCached
SwapCached: Memory that once was swapped out, is swapped back in but SwapCached
Memory that once was swapped out, is swapped back in but
still also is in the swapfile (if memory is needed it still also is in the swapfile (if memory is needed it
doesn't need to be swapped out AGAIN because it is already doesn't need to be swapped out AGAIN because it is already
in the swapfile. This saves I/O) in the swapfile. This saves I/O)
Active: Memory that has been used more recently and usually not Active
Memory that has been used more recently and usually not
reclaimed unless absolutely necessary. reclaimed unless absolutely necessary.
Inactive: Memory which has been less recently used. It is more Inactive
Memory which has been less recently used. It is more
eligible to be reclaimed for other purposes eligible to be reclaimed for other purposes
HighTotal: HighTotal, HighFree
HighFree: Highmem is all memory above ~860MB of physical memory Highmem is all memory above ~860MB of physical memory
Highmem areas are for use by userspace programs, or Highmem areas are for use by userspace programs, or
for the pagecache. The kernel must use tricks to access for the pagecache. The kernel must use tricks to access
this memory, making it slower to access than lowmem. this memory, making it slower to access than lowmem.
LowTotal: LowTotal, LowFree
LowFree: Lowmem is memory which can be used for everything that Lowmem is memory which can be used for everything that
highmem can be used for, but it is also available for the highmem can be used for, but it is also available for the
kernel's use for its own data structures. Among many kernel's use for its own data structures. Among many
other things, it is where everything from the Slab is other things, it is where everything from the Slab is
allocated. Bad things happen when you're out of lowmem. allocated. Bad things happen when you're out of lowmem.
SwapTotal: total amount of swap space available SwapTotal
SwapFree: Memory which has been evicted from RAM, and is temporarily total amount of swap space available
SwapFree
Memory which has been evicted from RAM, and is temporarily
on the disk on the disk
Dirty: Memory which is waiting to get written back to the disk Dirty
Writeback: Memory which is actively being written back to the disk Memory which is waiting to get written back to the disk
AnonPages: Non-file backed pages mapped into userspace page tables Writeback
HardwareCorrupted: The amount of RAM/memory in KB, the kernel identifies as Memory which is actively being written back to the disk
AnonPages
Non-file backed pages mapped into userspace page tables
HardwareCorrupted
The amount of RAM/memory in KB, the kernel identifies as
corrupted. corrupted.
AnonHugePages: Non-file backed huge pages mapped into userspace page tables AnonHugePages
Mapped: files which have been mmaped, such as libraries Non-file backed huge pages mapped into userspace page tables
Shmem: Total memory used by shared memory (shmem) and tmpfs Mapped
ShmemHugePages: Memory used by shared memory (shmem) and tmpfs allocated files which have been mmaped, such as libraries
Shmem
Total memory used by shared memory (shmem) and tmpfs
ShmemHugePages
Memory used by shared memory (shmem) and tmpfs allocated
with huge pages with huge pages
ShmemPmdMapped: Shared memory mapped into userspace with huge pages ShmemPmdMapped
KReclaimable: Kernel allocations that the kernel will attempt to reclaim Shared memory mapped into userspace with huge pages
KReclaimable
Kernel allocations that the kernel will attempt to reclaim
under memory pressure. Includes SReclaimable (below), and other under memory pressure. Includes SReclaimable (below), and other
direct allocations with a shrinker. direct allocations with a shrinker.
Slab: in-kernel data structures cache Slab
SReclaimable: Part of Slab, that might be reclaimed, such as caches in-kernel data structures cache
SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure SReclaimable
PageTables: amount of memory dedicated to the lowest level of page Part of Slab, that might be reclaimed, such as caches
SUnreclaim
Part of Slab, that cannot be reclaimed on memory pressure
PageTables
amount of memory dedicated to the lowest level of page
tables. tables.
NFS_Unstable: NFS pages sent to the server, but not yet committed to stable NFS_Unstable
NFS pages sent to the server, but not yet committed to stable
storage storage
Bounce: Memory used for block device "bounce buffers" Bounce
WritebackTmp: Memory used by FUSE for temporary writeback buffers Memory used for block device "bounce buffers"
CommitLimit: Based on the overcommit ratio ('vm.overcommit_ratio'), WritebackTmp
Memory used by FUSE for temporary writeback buffers
CommitLimit
Based on the overcommit ratio ('vm.overcommit_ratio'),
this is the total amount of memory currently available to this is the total amount of memory currently available to
be allocated on the system. This limit is only adhered to be allocated on the system. This limit is only adhered to
if strict overcommit accounting is enabled (mode 2 in if strict overcommit accounting is enabled (mode 2 in
'vm.overcommit_memory'). 'vm.overcommit_memory').
The CommitLimit is calculated with the following formula:
CommitLimit = ([total RAM pages] - [total huge TLB pages]) * The CommitLimit is calculated with the following formula::
overcommit_ratio / 100 + [total swap pages]
CommitLimit = ([total RAM pages] - [total huge TLB pages]) *
overcommit_ratio / 100 + [total swap pages]
For example, on a system with 1G of physical RAM and 7G For example, on a system with 1G of physical RAM and 7G
of swap with a `vm.overcommit_ratio` of 30 it would of swap with a `vm.overcommit_ratio` of 30 it would
yield a CommitLimit of 7.3G. yield a CommitLimit of 7.3G.
For more details, see the memory overcommit documentation For more details, see the memory overcommit documentation
in vm/overcommit-accounting. in vm/overcommit-accounting.
Committed_AS: The amount of memory presently allocated on the system. Committed_AS
The amount of memory presently allocated on the system.
The committed memory is a sum of all of the memory which The committed memory is a sum of all of the memory which
has been allocated by processes, even if it has not been has been allocated by processes, even if it has not been
"used" by them as of yet. A process which malloc()'s 1G "used" by them as of yet. A process which malloc()'s 1G
...@@ -1005,21 +1080,25 @@ Committed_AS: The amount of memory presently allocated on the system. ...@@ -1005,21 +1080,25 @@ Committed_AS: The amount of memory presently allocated on the system.
This is useful if one needs to guarantee that processes will This is useful if one needs to guarantee that processes will
not fail due to lack of memory once that memory has been not fail due to lack of memory once that memory has been
successfully allocated. successfully allocated.
VmallocTotal: total size of vmalloc memory area VmallocTotal
VmallocUsed: amount of vmalloc area which is used total size of vmalloc memory area
VmallocChunk: largest contiguous block of vmalloc area which is free VmallocUsed
Percpu: Memory allocated to the percpu allocator used to back percpu amount of vmalloc area which is used
VmallocChunk
largest contiguous block of vmalloc area which is free
Percpu
Memory allocated to the percpu allocator used to back percpu
allocations. This stat excludes the cost of metadata. allocations. This stat excludes the cost of metadata.
.............................................................................. vmallocinfo
~~~~~~~~~~~
vmallocinfo:
Provides information about vmalloced/vmaped areas. One line per area, Provides information about vmalloced/vmaped areas. One line per area,
containing the virtual address range of the area, size in bytes, containing the virtual address range of the area, size in bytes,
caller information of the creator, and optional information depending caller information of the creator, and optional information depending
on the kind of area : on the kind of area :
========== ===================================================
pages=nr number of pages pages=nr number of pages
phys=addr if a physical address was specified phys=addr if a physical address was specified
ioremap I/O mapping (ioremap() and friends) ioremap I/O mapping (ioremap() and friends)
...@@ -1029,49 +1108,54 @@ on the kind of area : ...@@ -1029,49 +1108,54 @@ on the kind of area :
vpages buffer for pages pointers was vmalloced (huge area) vpages buffer for pages pointers was vmalloced (huge area)
N<node>=nr (Only on NUMA kernels) N<node>=nr (Only on NUMA kernels)
Number of pages allocated on memory node <node> Number of pages allocated on memory node <node>
========== ===================================================
> cat /proc/vmallocinfo
0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ... ::
/0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128
0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ... > cat /proc/vmallocinfo
/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64 0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ...
0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f... /0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128
phys=7fee8000 ioremap 0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ...
0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f... /0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64
phys=7fee7000 ioremap 0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f...
0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210 phys=7fee8000 ioremap
0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ... 0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f...
/0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3 phys=7fee7000 ioremap
0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ... 0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210
pages=2 vmalloc N1=2 0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ...
0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ... /0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3
/0x130 [x_tables] pages=4 vmalloc N0=4 0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ...
0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ... pages=2 vmalloc N1=2
pages=14 vmalloc N2=14 0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ...
0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ... /0x130 [x_tables] pages=4 vmalloc N0=4
pages=4 vmalloc N1=4 0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ...
0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ... pages=14 vmalloc N2=14
pages=2 vmalloc N1=2 0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ...
0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ... pages=4 vmalloc N1=4
pages=10 vmalloc N0=10 0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ...
pages=2 vmalloc N1=2
.............................................................................. 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ...
pages=10 vmalloc N0=10
softirqs:
softirqs
~~~~~~~~
Provides counts of softirq handlers serviced since boot time, for each cpu. Provides counts of softirq handlers serviced since boot time, for each cpu.
> cat /proc/softirqs ::
CPU0 CPU1 CPU2 CPU3
HI: 0 0 0 0 > cat /proc/softirqs
TIMER: 27166 27120 27097 27034 CPU0 CPU1 CPU2 CPU3
NET_TX: 0 0 0 17 HI: 0 0 0 0
NET_RX: 42 0 0 39 TIMER: 27166 27120 27097 27034
BLOCK: 0 0 107 1121 NET_TX: 0 0 0 17
TASKLET: 0 0 0 290 NET_RX: 42 0 0 39
SCHED: 27035 26983 26971 26746 BLOCK: 0 0 107 1121
HRTIMER: 0 0 0 0 TASKLET: 0 0 0 290
RCU: 1678 1769 2178 2250 SCHED: 27035 26983 26971 26746
HRTIMER: 0 0 0 0
RCU: 1678 1769 2178 2250
1.3 IDE devices in /proc/ide 1.3 IDE devices in /proc/ide
...@@ -1083,7 +1167,7 @@ file drivers and a link for each IDE device, pointing to the device directory ...@@ -1083,7 +1167,7 @@ file drivers and a link for each IDE device, pointing to the device directory
in the controller specific subtree. in the controller specific subtree.
The file drivers contains general information about the drivers used for the The file drivers contains general information about the drivers used for the
IDE devices: IDE devices::
> cat /proc/ide/drivers > cat /proc/ide/drivers
ide-cdrom version 4.53 ide-cdrom version 4.53
...@@ -1094,57 +1178,61 @@ subdirectories. These are named ide0, ide1 and so on. Each of these ...@@ -1094,57 +1178,61 @@ subdirectories. These are named ide0, ide1 and so on. Each of these
directories contains the files shown in table 1-6. directories contains the files shown in table 1-6.
Table 1-6: IDE controller info in /proc/ide/ide? .. table:: Table 1-6: IDE controller info in /proc/ide/ide?
..............................................................................
File Content ======= =======================================
channel IDE channel (0 or 1) File Content
config Configuration (only for PCI/IDE bridge) ======= =======================================
mate Mate name channel IDE channel (0 or 1)
model Type/Chipset of IDE controller config Configuration (only for PCI/IDE bridge)
.............................................................................. mate Mate name
model Type/Chipset of IDE controller
======= =======================================
Each device connected to a controller has a separate subdirectory in the Each device connected to a controller has a separate subdirectory in the
controllers directory. The files listed in table 1-7 are contained in these controllers directory. The files listed in table 1-7 are contained in these
directories. directories.
Table 1-7: IDE device information .. table:: Table 1-7: IDE device information
..............................................................................
File Content ================ ==========================================
cache The cache File Content
capacity Capacity of the medium (in 512Byte blocks) ================ ==========================================
driver driver and version cache The cache
geometry physical and logical geometry capacity Capacity of the medium (in 512Byte blocks)
identify device identify block driver driver and version
media media type geometry physical and logical geometry
model device identifier identify device identify block
settings device setup media media type
smart_thresholds IDE disk management thresholds model device identifier
smart_values IDE disk management values settings device setup
.............................................................................. smart_thresholds IDE disk management thresholds
smart_values IDE disk management values
The most interesting file is settings. This file contains a nice overview of ================ ==========================================
the drive parameters:
The most interesting file is ``settings``. This file contains a nice
# cat /proc/ide/ide0/hda/settings overview of the drive parameters::
name value min max mode
---- ----- --- --- ---- # cat /proc/ide/ide0/hda/settings
bios_cyl 526 0 65535 rw name value min max mode
bios_head 255 0 255 rw ---- ----- --- --- ----
bios_sect 63 0 63 rw bios_cyl 526 0 65535 rw
breada_readahead 4 0 127 rw bios_head 255 0 255 rw
bswap 0 0 1 r bios_sect 63 0 63 rw
file_readahead 72 0 2097151 rw breada_readahead 4 0 127 rw
io_32bit 0 0 3 rw bswap 0 0 1 r
keepsettings 0 0 1 rw file_readahead 72 0 2097151 rw
max_kb_per_request 122 1 127 rw io_32bit 0 0 3 rw
multcount 0 0 8 rw keepsettings 0 0 1 rw
nice1 1 0 1 rw max_kb_per_request 122 1 127 rw
nowerr 0 0 1 rw multcount 0 0 8 rw
pio_mode write-only 0 255 w nice1 1 0 1 rw
slow 0 0 1 rw nowerr 0 0 1 rw
unmaskirq 0 0 1 rw pio_mode write-only 0 255 w
using_dma 0 0 1 rw slow 0 0 1 rw
unmaskirq 0 0 1 rw
using_dma 0 0 1 rw
1.4 Networking info in /proc/net 1.4 Networking info in /proc/net
...@@ -1155,67 +1243,70 @@ additional values you get for IP version 6 if you configure the kernel to ...@@ -1155,67 +1243,70 @@ additional values you get for IP version 6 if you configure the kernel to
support this. Table 1-9 lists the files and their meaning. support this. Table 1-9 lists the files and their meaning.
Table 1-8: IPv6 info in /proc/net .. table:: Table 1-8: IPv6 info in /proc/net
..............................................................................
File Content ========== =====================================================
udp6 UDP sockets (IPv6) File Content
tcp6 TCP sockets (IPv6) ========== =====================================================
raw6 Raw device statistics (IPv6) udp6 UDP sockets (IPv6)
igmp6 IP multicast addresses, which this host joined (IPv6) tcp6 TCP sockets (IPv6)
if_inet6 List of IPv6 interface addresses raw6 Raw device statistics (IPv6)
ipv6_route Kernel routing table for IPv6 igmp6 IP multicast addresses, which this host joined (IPv6)
rt6_stats Global IPv6 routing tables statistics if_inet6 List of IPv6 interface addresses
sockstat6 Socket statistics (IPv6) ipv6_route Kernel routing table for IPv6
snmp6 Snmp data (IPv6) rt6_stats Global IPv6 routing tables statistics
.............................................................................. sockstat6 Socket statistics (IPv6)
snmp6 Snmp data (IPv6)
========== =====================================================
Table 1-9: Network info in /proc/net
.............................................................................. .. table:: Table 1-9: Network info in /proc/net
File Content
arp Kernel ARP table ============= ================================================================
dev network devices with statistics File Content
============= ================================================================
arp Kernel ARP table
dev network devices with statistics
dev_mcast the Layer2 multicast groups a device is listening too dev_mcast the Layer2 multicast groups a device is listening too
(interface index, label, number of references, number of bound (interface index, label, number of references, number of bound
addresses). addresses).
dev_stat network device status dev_stat network device status
ip_fwchains Firewall chain linkage ip_fwchains Firewall chain linkage
ip_fwnames Firewall chain names ip_fwnames Firewall chain names
ip_masq Directory containing the masquerading tables ip_masq Directory containing the masquerading tables
ip_masquerade Major masquerading table ip_masquerade Major masquerading table
netstat Network statistics netstat Network statistics
raw raw device statistics raw raw device statistics
route Kernel routing table route Kernel routing table
rpc Directory containing rpc info rpc Directory containing rpc info
rt_cache Routing cache rt_cache Routing cache
snmp SNMP data snmp SNMP data
sockstat Socket statistics sockstat Socket statistics
tcp TCP sockets tcp TCP sockets
udp UDP sockets udp UDP sockets
unix UNIX domain sockets unix UNIX domain sockets
wireless Wireless interface data (Wavelan etc) wireless Wireless interface data (Wavelan etc)
igmp IP multicast addresses, which this host joined igmp IP multicast addresses, which this host joined
psched Global packet scheduler parameters. psched Global packet scheduler parameters.
netlink List of PF_NETLINK sockets netlink List of PF_NETLINK sockets
ip_mr_vifs List of multicast virtual interfaces ip_mr_vifs List of multicast virtual interfaces
ip_mr_cache List of multicast routing cache ip_mr_cache List of multicast routing cache
.............................................................................. ============= ================================================================
You can use this information to see which network devices are available in You can use this information to see which network devices are available in
your system and how much traffic was routed over those devices: your system and how much traffic was routed over those devices::
> cat /proc/net/dev > cat /proc/net/dev
Inter-|Receive |[... Inter-|Receive |[...
face |bytes packets errs drop fifo frame compressed multicast|[... face |bytes packets errs drop fifo frame compressed multicast|[...
lo: 908188 5596 0 0 0 0 0 0 [... lo: 908188 5596 0 0 0 0 0 0 [...
ppp0:15475140 20721 410 0 0 410 0 0 [... ppp0:15475140 20721 410 0 0 410 0 0 [...
eth0: 614530 7085 0 0 0 0 0 1 [... eth0: 614530 7085 0 0 0 0 0 1 [...
...] Transmit ...] Transmit
...] bytes packets errs drop fifo colls carrier compressed ...] bytes packets errs drop fifo colls carrier compressed
...] 908188 5596 0 0 0 0 0 0 ...] 908188 5596 0 0 0 0 0 0
...] 1375103 17405 0 0 0 0 0 0 ...] 1375103 17405 0 0 0 0 0 0
...] 1703981 5535 0 0 0 3 0 0 ...] 1703981 5535 0 0 0 3 0 0
In addition, each Channel Bond interface has its own directory. For In addition, each Channel Bond interface has its own directory. For
example, the bond0 device will have a directory called /proc/net/bond0/. example, the bond0 device will have a directory called /proc/net/bond0/.
...@@ -1228,62 +1319,62 @@ many times the slaves link has failed. ...@@ -1228,62 +1319,62 @@ many times the slaves link has failed.
If you have a SCSI host adapter in your system, you'll find a subdirectory If you have a SCSI host adapter in your system, you'll find a subdirectory
named after the driver for this adapter in /proc/scsi. You'll also see a list named after the driver for this adapter in /proc/scsi. You'll also see a list
of all recognized SCSI devices in /proc/scsi: of all recognized SCSI devices in /proc/scsi::
>cat /proc/scsi/scsi >cat /proc/scsi/scsi
Attached devices: Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00 Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: IBM Model: DGHS09U Rev: 03E0 Vendor: IBM Model: DGHS09U Rev: 03E0
Type: Direct-Access ANSI SCSI revision: 03 Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 06 Lun: 00 Host: scsi0 Channel: 00 Id: 06 Lun: 00
Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04 Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04
Type: CD-ROM ANSI SCSI revision: 02 Type: CD-ROM ANSI SCSI revision: 02
The directory named after the driver has one file for each adapter found in The directory named after the driver has one file for each adapter found in
the system. These files contain information about the controller, including the system. These files contain information about the controller, including
the used IRQ and the IO address range. The amount of information shown is the used IRQ and the IO address range. The amount of information shown is
dependent on the adapter you use. The example shows the output for an Adaptec dependent on the adapter you use. The example shows the output for an Adaptec
AHA-2940 SCSI adapter: AHA-2940 SCSI adapter::
> cat /proc/scsi/aic7xxx/0 > cat /proc/scsi/aic7xxx/0
Adaptec AIC7xxx driver version: 5.1.19/3.2.4 Adaptec AIC7xxx driver version: 5.1.19/3.2.4
Compile Options: Compile Options:
TCQ Enabled By Default : Disabled TCQ Enabled By Default : Disabled
AIC7XXX_PROC_STATS : Disabled AIC7XXX_PROC_STATS : Disabled
AIC7XXX_RESET_DELAY : 5 AIC7XXX_RESET_DELAY : 5
Adapter Configuration: Adapter Configuration:
SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
Ultra Wide Controller Ultra Wide Controller
PCI MMAPed I/O Base: 0xeb001000 PCI MMAPed I/O Base: 0xeb001000
Adapter SEEPROM Config: SEEPROM found and used. Adapter SEEPROM Config: SEEPROM found and used.
Adaptec SCSI BIOS: Enabled Adaptec SCSI BIOS: Enabled
IRQ: 10 IRQ: 10
SCBs: Active 0, Max Active 2, SCBs: Active 0, Max Active 2,
Allocated 15, HW 16, Page 255 Allocated 15, HW 16, Page 255
Interrupts: 160328 Interrupts: 160328
BIOS Control Word: 0x18b6 BIOS Control Word: 0x18b6
Adapter Control Word: 0x005b Adapter Control Word: 0x005b
Extended Translation: Enabled Extended Translation: Enabled
Disconnect Enable Flags: 0xffff Disconnect Enable Flags: 0xffff
Ultra Enable Flags: 0x0001 Ultra Enable Flags: 0x0001
Tag Queue Enable Flags: 0x0000 Tag Queue Enable Flags: 0x0000
Ordered Queue Tag Flags: 0x0000 Ordered Queue Tag Flags: 0x0000
Default Tag Queue Depth: 8 Default Tag Queue Depth: 8
Tagged Queue By Device array for aic7xxx host instance 0: Tagged Queue By Device array for aic7xxx host instance 0:
{255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255} {255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255}
Actual queue depth per device for aic7xxx host instance 0: Actual queue depth per device for aic7xxx host instance 0:
{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1} {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}
Statistics: Statistics:
(scsi0:0:0:0) (scsi0:0:0:0)
Device using Wide/Sync transfers at 40.0 MByte/sec, offset 8 Device using Wide/Sync transfers at 40.0 MByte/sec, offset 8
Transinfo settings: current(12/8/1/0), goal(12/8/1/0), user(12/15/1/0) Transinfo settings: current(12/8/1/0), goal(12/8/1/0), user(12/15/1/0)
Total transfers 160151 (74577 reads and 85574 writes) Total transfers 160151 (74577 reads and 85574 writes)
(scsi0:0:6:0) (scsi0:0:6:0)
Device using Narrow/Sync transfers at 5.0 MByte/sec, offset 15 Device using Narrow/Sync transfers at 5.0 MByte/sec, offset 15
Transinfo settings: current(50/15/0/0), goal(50/15/0/0), user(50/15/0/0) Transinfo settings: current(50/15/0/0), goal(50/15/0/0), user(50/15/0/0)
Total transfers 0 (0 reads and 0 writes) Total transfers 0 (0 reads and 0 writes)
1.6 Parallel port info in /proc/parport 1.6 Parallel port info in /proc/parport
...@@ -1296,18 +1387,20 @@ number (0,1,2,...). ...@@ -1296,18 +1387,20 @@ number (0,1,2,...).
These directories contain the four files shown in Table 1-10. These directories contain the four files shown in Table 1-10.
Table 1-10: Files in /proc/parport .. table:: Table 1-10: Files in /proc/parport
..............................................................................
File Content ========= ====================================================================
autoprobe Any IEEE-1284 device ID information that has been acquired. File Content
========= ====================================================================
autoprobe Any IEEE-1284 device ID information that has been acquired.
devices list of the device drivers using that port. A + will appear by the devices list of the device drivers using that port. A + will appear by the
name of the device currently using the port (it might not appear name of the device currently using the port (it might not appear
against any). against any).
hardware Parallel port's base address, IRQ line and DMA channel. hardware Parallel port's base address, IRQ line and DMA channel.
irq IRQ that parport is using for that port. This is in a separate irq IRQ that parport is using for that port. This is in a separate
file to allow you to alter it by writing a new value in (IRQ file to allow you to alter it by writing a new value in (IRQ
number or none). number or none).
.............................................................................. ========= ====================================================================
1.7 TTY info in /proc/tty 1.7 TTY info in /proc/tty
------------------------- -------------------------
...@@ -1317,29 +1410,31 @@ directory /proc/tty.You'll find entries for drivers and line disciplines in ...@@ -1317,29 +1410,31 @@ directory /proc/tty.You'll find entries for drivers and line disciplines in
this directory, as shown in Table 1-11. this directory, as shown in Table 1-11.
Table 1-11: Files in /proc/tty .. table:: Table 1-11: Files in /proc/tty
..............................................................................
File Content ============= ==============================================
drivers list of drivers and their usage File Content
ldiscs registered line disciplines ============= ==============================================
driver/serial usage statistic and status of single tty lines drivers list of drivers and their usage
.............................................................................. ldiscs registered line disciplines
driver/serial usage statistic and status of single tty lines
============= ==============================================
To see which tty's are currently in use, you can simply look into the file To see which tty's are currently in use, you can simply look into the file
/proc/tty/drivers: /proc/tty/drivers::
> cat /proc/tty/drivers > cat /proc/tty/drivers
pty_slave /dev/pts 136 0-255 pty:slave pty_slave /dev/pts 136 0-255 pty:slave
pty_master /dev/ptm 128 0-255 pty:master pty_master /dev/ptm 128 0-255 pty:master
pty_slave /dev/ttyp 3 0-255 pty:slave pty_slave /dev/ttyp 3 0-255 pty:slave
pty_master /dev/pty 2 0-255 pty:master pty_master /dev/pty 2 0-255 pty:master
serial /dev/cua 5 64-67 serial:callout serial /dev/cua 5 64-67 serial:callout
serial /dev/ttyS 4 64-67 serial serial /dev/ttyS 4 64-67 serial
/dev/tty0 /dev/tty0 4 0 system:vtmaster /dev/tty0 /dev/tty0 4 0 system:vtmaster
/dev/ptmx /dev/ptmx 5 2 system /dev/ptmx /dev/ptmx 5 2 system
/dev/console /dev/console 5 1 system:console /dev/console /dev/console 5 1 system:console
/dev/tty /dev/tty 5 0 system:/dev/tty /dev/tty /dev/tty 5 0 system:/dev/tty
unknown /dev/tty 4 1-63 console unknown /dev/tty 4 1-63 console
1.8 Miscellaneous kernel statistics in /proc/stat 1.8 Miscellaneous kernel statistics in /proc/stat
...@@ -1347,7 +1442,7 @@ To see which tty's are currently in use, you can simply look into the file ...@@ -1347,7 +1442,7 @@ To see which tty's are currently in use, you can simply look into the file
Various pieces of information about kernel activity are available in the Various pieces of information about kernel activity are available in the
/proc/stat file. All of the numbers reported in this file are aggregates /proc/stat file. All of the numbers reported in this file are aggregates
since the system first booted. For a quick look, simply cat the file: since the system first booted. For a quick look, simply cat the file::
> cat /proc/stat > cat /proc/stat
cpu 2255 34 2290 22625563 6290 127 456 0 0 0 cpu 2255 34 2290 22625563 6290 127 456 0 0 0
...@@ -1372,6 +1467,7 @@ second). The meanings of the columns are as follows, from left to right: ...@@ -1372,6 +1467,7 @@ second). The meanings of the columns are as follows, from left to right:
- idle: twiddling thumbs - idle: twiddling thumbs
- iowait: In a word, iowait stands for waiting for I/O to complete. But there - iowait: In a word, iowait stands for waiting for I/O to complete. But there
are several problems: are several problems:
1. Cpu will not wait for I/O to complete, iowait is the time that a task is 1. Cpu will not wait for I/O to complete, iowait is the time that a task is
waiting for I/O to complete. When cpu goes into idle state for waiting for I/O to complete. When cpu goes into idle state for
outstanding task io, another task will be scheduled on this CPU. outstanding task io, another task will be scheduled on this CPU.
...@@ -1379,6 +1475,7 @@ second). The meanings of the columns are as follows, from left to right: ...@@ -1379,6 +1475,7 @@ second). The meanings of the columns are as follows, from left to right:
on any CPU, so the iowait of each CPU is difficult to calculate. on any CPU, so the iowait of each CPU is difficult to calculate.
3. The value of iowait field in /proc/stat will decrease in certain 3. The value of iowait field in /proc/stat will decrease in certain
conditions. conditions.
So, the iowait is not reliable by reading from /proc/stat. So, the iowait is not reliable by reading from /proc/stat.
- irq: servicing interrupts - irq: servicing interrupts
- softirq: servicing softirqs - softirq: servicing softirqs
...@@ -1422,18 +1519,19 @@ Information about mounted ext4 file systems can be found in ...@@ -1422,18 +1519,19 @@ Information about mounted ext4 file systems can be found in
/proc/fs/ext4/dm-0). The files in each per-device directory are shown /proc/fs/ext4/dm-0). The files in each per-device directory are shown
in Table 1-12, below. in Table 1-12, below.
Table 1-12: Files in /proc/fs/ext4/<devname> .. table:: Table 1-12: Files in /proc/fs/ext4/<devname>
..............................................................................
File Content ============== ==========================================================
File Content
mb_groups details of multiblock allocator buddy cache of free blocks mb_groups details of multiblock allocator buddy cache of free blocks
.............................................................................. ============== ==========================================================
2.0 /proc/consoles 2.0 /proc/consoles
------------------ ------------------
Shows registered system console lines. Shows registered system console lines.
To see which character device lines are currently used for the system console To see which character device lines are currently used for the system console
/dev/console, you may simply look into the file /proc/consoles: /dev/console, you may simply look into the file /proc/consoles::
> cat /proc/consoles > cat /proc/consoles
tty0 -WU (ECp) 4:7 tty0 -WU (ECp) 4:7
...@@ -1441,41 +1539,45 @@ To see which character device lines are currently used for the system console ...@@ -1441,41 +1539,45 @@ To see which character device lines are currently used for the system console
The columns are: The columns are:
device name of the device +--------------------+-------------------------------------------------------+
operations R = can do read operations | device | name of the device |
W = can do write operations +====================+=======================================================+
U = can do unblank | operations | * R = can do read operations |
flags E = it is enabled | | * W = can do write operations |
C = it is preferred console | | * U = can do unblank |
B = it is primary boot console +--------------------+-------------------------------------------------------+
p = it is used for printk buffer | flags | * E = it is enabled |
b = it is not a TTY but a Braille device | | * C = it is preferred console |
a = it is safe to use when cpu is offline | | * B = it is primary boot console |
major:minor major and minor number of the device separated by a colon | | * p = it is used for printk buffer |
| | * b = it is not a TTY but a Braille device |
| | * a = it is safe to use when cpu is offline |
+--------------------+-------------------------------------------------------+
| major:minor | major and minor number of the device separated by a |
| | colon |
+--------------------+-------------------------------------------------------+
------------------------------------------------------------------------------
Summary Summary
------------------------------------------------------------------------------ -------
The /proc file system serves information about the running system. It not only The /proc file system serves information about the running system. It not only
allows access to process data but also allows you to request the kernel status allows access to process data but also allows you to request the kernel status
by reading files in the hierarchy. by reading files in the hierarchy.
The directory structure of /proc reflects the types of information and makes The directory structure of /proc reflects the types of information and makes
it easy, if not obvious, where to look for specific data. it easy, if not obvious, where to look for specific data.
------------------------------------------------------------------------------
------------------------------------------------------------------------------ Chapter 2: Modifying System Parameters
CHAPTER 2: MODIFYING SYSTEM PARAMETERS ======================================
------------------------------------------------------------------------------
------------------------------------------------------------------------------
In This Chapter In This Chapter
------------------------------------------------------------------------------ ---------------
* Modifying kernel parameters by writing into files found in /proc/sys * Modifying kernel parameters by writing into files found in /proc/sys
* Exploring the files which modify certain parameters * Exploring the files which modify certain parameters
* Review of the /proc/sys file tree * Review of the /proc/sys file tree
------------------------------------------------------------------------------
------------------------------------------------------------------------------
A very interesting part of /proc is the directory /proc/sys. This is not only A very interesting part of /proc is the directory /proc/sys. This is not only
a source of information, it also allows you to change parameters within the a source of information, it also allows you to change parameters within the
...@@ -1503,19 +1605,18 @@ kernels, and became part of it in version 2.2.1 of the Linux kernel. ...@@ -1503,19 +1605,18 @@ kernels, and became part of it in version 2.2.1 of the Linux kernel.
Please see: Documentation/admin-guide/sysctl/ directory for descriptions of these Please see: Documentation/admin-guide/sysctl/ directory for descriptions of these
entries. entries.
------------------------------------------------------------------------------
Summary Summary
------------------------------------------------------------------------------ -------
Certain aspects of kernel behavior can be modified at runtime, without the Certain aspects of kernel behavior can be modified at runtime, without the
need to recompile the kernel, or even to reboot the system. The files in the need to recompile the kernel, or even to reboot the system. The files in the
/proc/sys tree can not only be read, but also modified. You can use the echo /proc/sys tree can not only be read, but also modified. You can use the echo
command to write value into these files, thereby changing the default settings command to write value into these files, thereby changing the default settings
of the kernel. of the kernel.
------------------------------------------------------------------------------
------------------------------------------------------------------------------
CHAPTER 3: PER-PROCESS PARAMETERS Chapter 3: Per-process Parameters
------------------------------------------------------------------------------ =================================
3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score 3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score
-------------------------------------------------------------------------------- --------------------------------------------------------------------------------
...@@ -1588,26 +1689,28 @@ process should be killed in an out-of-memory situation. ...@@ -1588,26 +1689,28 @@ process should be killed in an out-of-memory situation.
This file contains IO statistics for each running process This file contains IO statistics for each running process
Example Example
------- ~~~~~~~
::
test:/tmp # dd if=/dev/zero of=/tmp/test.dat & test:/tmp # dd if=/dev/zero of=/tmp/test.dat &
[1] 3828 [1] 3828
test:/tmp # cat /proc/3828/io test:/tmp # cat /proc/3828/io
rchar: 323934931 rchar: 323934931
wchar: 323929600 wchar: 323929600
syscr: 632687 syscr: 632687
syscw: 632675 syscw: 632675
read_bytes: 0 read_bytes: 0
write_bytes: 323932160 write_bytes: 323932160
cancelled_write_bytes: 0 cancelled_write_bytes: 0
Description Description
----------- ~~~~~~~~~~~
rchar rchar
----- ^^^^^
I/O counter: chars read I/O counter: chars read
The number of bytes which this task has caused to be read from storage. This The number of bytes which this task has caused to be read from storage. This
...@@ -1618,7 +1721,7 @@ pagecache) ...@@ -1618,7 +1721,7 @@ pagecache)
wchar wchar
----- ^^^^^
I/O counter: chars written I/O counter: chars written
The number of bytes which this task has caused, or shall cause to be written The number of bytes which this task has caused, or shall cause to be written
...@@ -1626,7 +1729,7 @@ to disk. Similar caveats apply here as with rchar. ...@@ -1626,7 +1729,7 @@ to disk. Similar caveats apply here as with rchar.
syscr syscr
----- ^^^^^
I/O counter: read syscalls I/O counter: read syscalls
Attempt to count the number of read I/O operations, i.e. syscalls like read() Attempt to count the number of read I/O operations, i.e. syscalls like read()
...@@ -1634,7 +1737,7 @@ and pread(). ...@@ -1634,7 +1737,7 @@ and pread().
syscw syscw
----- ^^^^^
I/O counter: write syscalls I/O counter: write syscalls
Attempt to count the number of write I/O operations, i.e. syscalls like Attempt to count the number of write I/O operations, i.e. syscalls like
...@@ -1642,7 +1745,7 @@ write() and pwrite(). ...@@ -1642,7 +1745,7 @@ write() and pwrite().
read_bytes read_bytes
---------- ^^^^^^^^^^
I/O counter: bytes read I/O counter: bytes read
Attempt to count the number of bytes which this process really did cause to Attempt to count the number of bytes which this process really did cause to
...@@ -1652,7 +1755,7 @@ CIFS at a later time> ...@@ -1652,7 +1755,7 @@ CIFS at a later time>
write_bytes write_bytes
----------- ^^^^^^^^^^^
I/O counter: bytes written I/O counter: bytes written
Attempt to count the number of bytes which this process caused to be sent to Attempt to count the number of bytes which this process caused to be sent to
...@@ -1660,7 +1763,7 @@ the storage layer. This is done at page-dirtying time. ...@@ -1660,7 +1763,7 @@ the storage layer. This is done at page-dirtying time.
cancelled_write_bytes cancelled_write_bytes
--------------------- ^^^^^^^^^^^^^^^^^^^^^
The big inaccuracy here is truncate. If a process writes 1MB to a file and The big inaccuracy here is truncate. If a process writes 1MB to a file and
then deletes the file, it will in fact perform no writeout. But it will have then deletes the file, it will in fact perform no writeout. But it will have
...@@ -1673,12 +1776,11 @@ from the truncating task's write_bytes, but there is information loss in doing ...@@ -1673,12 +1776,11 @@ from the truncating task's write_bytes, but there is information loss in doing
that. that.
Note .. Note::
----
At its current implementation state, this is a bit racy on 32-bit machines: if At its current implementation state, this is a bit racy on 32-bit machines:
process A reads process B's /proc/pid/io while process B is updating one of if process A reads process B's /proc/pid/io while process B is updating one
those 64-bit counters, process A could see an intermediate result. of those 64-bit counters, process A could see an intermediate result.
More information about this can be found within the taskstats documentation in More information about this can be found within the taskstats documentation in
...@@ -1698,12 +1800,13 @@ of memory types. If a bit of the bitmask is set, memory segments of the ...@@ -1698,12 +1800,13 @@ of memory types. If a bit of the bitmask is set, memory segments of the
corresponding memory type are dumped, otherwise they are not dumped. corresponding memory type are dumped, otherwise they are not dumped.
The following 9 memory types are supported: The following 9 memory types are supported:
- (bit 0) anonymous private memory - (bit 0) anonymous private memory
- (bit 1) anonymous shared memory - (bit 1) anonymous shared memory
- (bit 2) file-backed private memory - (bit 2) file-backed private memory
- (bit 3) file-backed shared memory - (bit 3) file-backed shared memory
- (bit 4) ELF header pages in file-backed private memory areas (it is - (bit 4) ELF header pages in file-backed private memory areas (it is
effective only if the bit 2 is cleared) effective only if the bit 2 is cleared)
- (bit 5) hugetlb private memory - (bit 5) hugetlb private memory
- (bit 6) hugetlb shared memory - (bit 6) hugetlb shared memory
- (bit 7) DAX private memory - (bit 7) DAX private memory
...@@ -1719,13 +1822,13 @@ The default value of coredump_filter is 0x33; this means all anonymous memory ...@@ -1719,13 +1822,13 @@ The default value of coredump_filter is 0x33; this means all anonymous memory
segments, ELF header pages and hugetlb private memory are dumped. segments, ELF header pages and hugetlb private memory are dumped.
If you don't want to dump all shared memory segments attached to pid 1234, If you don't want to dump all shared memory segments attached to pid 1234,
write 0x31 to the process's proc file. write 0x31 to the process's proc file::
$ echo 0x31 > /proc/1234/coredump_filter $ echo 0x31 > /proc/1234/coredump_filter
When a new process is created, the process inherits the bitmask status from its When a new process is created, the process inherits the bitmask status from its
parent. It is useful to set up coredump_filter before the program runs. parent. It is useful to set up coredump_filter before the program runs.
For example: For example::
$ echo 0x7 > /proc/self/coredump_filter $ echo 0x7 > /proc/self/coredump_filter
$ ./some_program $ ./some_program
...@@ -1733,35 +1836,37 @@ For example: ...@@ -1733,35 +1836,37 @@ For example:
3.5 /proc/<pid>/mountinfo - Information about mounts 3.5 /proc/<pid>/mountinfo - Information about mounts
-------------------------------------------------------- --------------------------------------------------------
This file contains lines of the form: This file contains lines of the form::
36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
(1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) (1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11)
(1) mount ID: unique identifier of the mount (may be reused after umount) (1) mount ID: unique identifier of the mount (may be reused after umount)
(2) parent ID: ID of parent (or of self for the top of the mount tree) (2) parent ID: ID of parent (or of self for the top of the mount tree)
(3) major:minor: value of st_dev for files on filesystem (3) major:minor: value of st_dev for files on filesystem
(4) root: root of the mount within the filesystem (4) root: root of the mount within the filesystem
(5) mount point: mount point relative to the process's root (5) mount point: mount point relative to the process's root
(6) mount options: per mount options (6) mount options: per mount options
(7) optional fields: zero or more fields of the form "tag[:value]" (7) optional fields: zero or more fields of the form "tag[:value]"
(8) separator: marks the end of the optional fields (8) separator: marks the end of the optional fields
(9) filesystem type: name of filesystem of the form "type[.subtype]" (9) filesystem type: name of filesystem of the form "type[.subtype]"
(10) mount source: filesystem specific information or "none" (10) mount source: filesystem specific information or "none"
(11) super options: per super block options (11) super options: per super block options
Parsers should ignore all unrecognised optional fields. Currently the Parsers should ignore all unrecognised optional fields. Currently the
possible optional fields are: possible optional fields are:
shared:X mount is shared in peer group X ================ ==============================================================
master:X mount is slave to peer group X shared:X mount is shared in peer group X
propagate_from:X mount is slave and receives propagation from peer group X (*) master:X mount is slave to peer group X
unbindable mount is unbindable propagate_from:X mount is slave and receives propagation from peer group X [#]_
unbindable mount is unbindable
================ ==============================================================
(*) X is the closest dominant peer group under the process's root. If .. [#] X is the closest dominant peer group under the process's root. If
X is the immediate master of the mount, or if there's no dominant peer X is the immediate master of the mount, or if there's no dominant peer
group under the same root, then only the "master:X" field is present group under the same root, then only the "master:X" field is present
and not the "propagate_from:X" field. and not the "propagate_from:X" field.
For more information on mount propagation see: For more information on mount propagation see:
...@@ -1804,77 +1909,86 @@ created with [see open(2) for details] and 'mnt_id' represents mount ID of ...@@ -1804,77 +1909,86 @@ created with [see open(2) for details] and 'mnt_id' represents mount ID of
the file system containing the opened file [see 3.5 /proc/<pid>/mountinfo the file system containing the opened file [see 3.5 /proc/<pid>/mountinfo
for details]. for details].
A typical output is A typical output is::
pos: 0 pos: 0
flags: 0100002 flags: 0100002
mnt_id: 19 mnt_id: 19
All locks associated with a file descriptor are shown in its fdinfo too. All locks associated with a file descriptor are shown in its fdinfo too::
lock: 1: FLOCK ADVISORY WRITE 359 00:13:11691 0 EOF lock: 1: FLOCK ADVISORY WRITE 359 00:13:11691 0 EOF
The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
pair provide additional information particular to the objects they represent. pair provide additional information particular to the objects they represent.
Eventfd files Eventfd files
~~~~~~~~~~~~~ ~~~~~~~~~~~~~
::
pos: 0 pos: 0
flags: 04002 flags: 04002
mnt_id: 9 mnt_id: 9
eventfd-count: 5a eventfd-count: 5a
where 'eventfd-count' is hex value of a counter. where 'eventfd-count' is hex value of a counter.
Signalfd files
~~~~~~~~~~~~~~
::
Signalfd files
~~~~~~~~~~~~~~
pos: 0 pos: 0
flags: 04002 flags: 04002
mnt_id: 9 mnt_id: 9
sigmask: 0000000000000200 sigmask: 0000000000000200
where 'sigmask' is hex value of the signal mask associated where 'sigmask' is hex value of the signal mask associated
with a file. with a file.
Epoll files
~~~~~~~~~~~
::
Epoll files
~~~~~~~~~~~
pos: 0 pos: 0
flags: 02 flags: 02
mnt_id: 9 mnt_id: 9
tfd: 5 events: 1d data: ffffffffffffffff pos:0 ino:61af sdev:7 tfd: 5 events: 1d data: ffffffffffffffff pos:0 ino:61af sdev:7
where 'tfd' is a target file descriptor number in decimal form, where 'tfd' is a target file descriptor number in decimal form,
'events' is events mask being watched and the 'data' is data 'events' is events mask being watched and the 'data' is data
associated with a target [see epoll(7) for more details]. associated with a target [see epoll(7) for more details].
The 'pos' is current offset of the target file in decimal form The 'pos' is current offset of the target file in decimal form
[see lseek(2)], 'ino' and 'sdev' are inode and device numbers [see lseek(2)], 'ino' and 'sdev' are inode and device numbers
where target file resides, all in hex format. where target file resides, all in hex format.
Fsnotify files Fsnotify files
~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
For inotify files the format is the following For inotify files the format is the following::
pos: 0 pos: 0
flags: 02000000 flags: 02000000
inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
where 'wd' is a watch descriptor in decimal form, ie a target file where 'wd' is a watch descriptor in decimal form, ie a target file
descriptor number, 'ino' and 'sdev' are inode and device where the descriptor number, 'ino' and 'sdev' are inode and device where the
target file resides and the 'mask' is the mask of events, all in hex target file resides and the 'mask' is the mask of events, all in hex
form [see inotify(7) for more details]. form [see inotify(7) for more details].
If the kernel was built with exportfs support, the path to the target If the kernel was built with exportfs support, the path to the target
file is encoded as a file handle. The file handle is provided by three file is encoded as a file handle. The file handle is provided by three
fields 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex fields 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex
format. format.
If the kernel is built without exportfs support the file handle won't be If the kernel is built without exportfs support the file handle won't be
printed out. printed out.
If there is no inotify mark attached yet the 'inotify' line will be omitted. If there is no inotify mark attached yet the 'inotify' line will be omitted.
For fanotify files the format is For fanotify files the format is::
pos: 0 pos: 0
flags: 02 flags: 02
...@@ -1883,20 +1997,22 @@ pair provide additional information particular to the objects they represent. ...@@ -1883,20 +1997,22 @@ pair provide additional information particular to the objects they represent.
fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003 fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4 fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
where fanotify 'flags' and 'event-flags' are values used in fanotify_init where fanotify 'flags' and 'event-flags' are values used in fanotify_init
call, 'mnt_id' is the mount point identifier, 'mflags' is the value of call, 'mnt_id' is the mount point identifier, 'mflags' is the value of
flags associated with mark which are tracked separately from events flags associated with mark which are tracked separately from events
mask. 'ino', 'sdev' are target inode and device, 'mask' is the events mask. 'ino', 'sdev' are target inode and device, 'mask' is the events
mask and 'ignored_mask' is the mask of events which are to be ignored. mask and 'ignored_mask' is the mask of events which are to be ignored.
All in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask' All in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask'
does provide information about flags and mask used in fanotify_mark does provide information about flags and mask used in fanotify_mark
call [see fsnotify manpage for details]. call [see fsnotify manpage for details].
While the first three lines are mandatory and always printed, the rest is
optional and may be omitted if no marks created yet.
While the first three lines are mandatory and always printed, the rest is Timerfd files
optional and may be omitted if no marks created yet. ~~~~~~~~~~~~~
Timerfd files ::
~~~~~~~~~~~~~
pos: 0 pos: 0
flags: 02 flags: 02
...@@ -1907,18 +2023,18 @@ pair provide additional information particular to the objects they represent. ...@@ -1907,18 +2023,18 @@ pair provide additional information particular to the objects they represent.
it_value: (0, 49406829) it_value: (0, 49406829)
it_interval: (1, 0) it_interval: (1, 0)
where 'clockid' is the clock type and 'ticks' is the number of the timer expirations where 'clockid' is the clock type and 'ticks' is the number of the timer expirations
that have occurred [see timerfd_create(2) for details]. 'settime flags' are that have occurred [see timerfd_create(2) for details]. 'settime flags' are
flags in octal form been used to setup the timer [see timerfd_settime(2) for flags in octal form been used to setup the timer [see timerfd_settime(2) for
details]. 'it_value' is remaining time until the timer exiration. details]. 'it_value' is remaining time until the timer exiration.
'it_interval' is the interval for the timer. Note the timer might be set up 'it_interval' is the interval for the timer. Note the timer might be set up
with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value' with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value'
still exhibits timer's remaining time. still exhibits timer's remaining time.
3.9 /proc/<pid>/map_files - Information about memory mapped files 3.9 /proc/<pid>/map_files - Information about memory mapped files
--------------------------------------------------------------------- ---------------------------------------------------------------------
This directory contains symbolic links which represent memory mapped files This directory contains symbolic links which represent memory mapped files
the process is maintaining. Example output: the process is maintaining. Example output::
| lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so | lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so
| lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so | lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so
...@@ -1976,17 +2092,22 @@ When CONFIG_PROC_PID_ARCH_STATUS is enabled, this file displays the ...@@ -1976,17 +2092,22 @@ When CONFIG_PROC_PID_ARCH_STATUS is enabled, this file displays the
architecture specific status of the task. architecture specific status of the task.
Example Example
------- ~~~~~~~
::
$ cat /proc/6753/arch_status $ cat /proc/6753/arch_status
AVX512_elapsed_ms: 8 AVX512_elapsed_ms: 8
Description Description
----------- ~~~~~~~~~~~
x86 specific entries: x86 specific entries:
--------------------- ~~~~~~~~~~~~~~~~~~~~~
AVX512_elapsed_ms:
------------------ AVX512_elapsed_ms:
^^^^^^^^^^^^^^^^^^
If AVX512 is supported on the machine, this entry shows the milliseconds If AVX512 is supported on the machine, this entry shows the milliseconds
elapsed since the last time AVX512 usage was recorded. The recording elapsed since the last time AVX512 usage was recorded. The recording
happens on a best effort basis when a task is scheduled out. This means happens on a best effort basis when a task is scheduled out. This means
...@@ -2010,17 +2131,18 @@ x86 specific entries: ...@@ -2010,17 +2131,18 @@ x86 specific entries:
the task is unlikely an AVX512 user, but depends on the workload and the the task is unlikely an AVX512 user, but depends on the workload and the
scheduling scenario, it also could be a false negative mentioned above. scheduling scenario, it also could be a false negative mentioned above.
------------------------------------------------------------------------------
Configuring procfs Configuring procfs
------------------------------------------------------------------------------ ------------------
4.1 Mount options 4.1 Mount options
--------------------- ---------------------
The following mount options are supported: The following mount options are supported:
========= ========================================================
hidepid= Set /proc/<pid>/ access mode. hidepid= Set /proc/<pid>/ access mode.
gid= Set the group authorized to learn processes information. gid= Set the group authorized to learn processes information.
========= ========================================================
hidepid=0 means classic mode - everybody may access all /proc/<pid>/ directories hidepid=0 means classic mode - everybody may access all /proc/<pid>/ directories
(default). (default).
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7