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Commit 3a978e55 authored by Paul Jackson's avatar Paul Jackson Committed by Linus Torvalds
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[PATCH] cpusets - big numa cpu and memory placement 

This my cpuset patch, with the following changes in the last two weeks:

 1) Updated to 2.6.8.1-mm1
 2) [Simon Derr <Simon.Derr@bull.net>] Fix new cpuset to begin empty,
    not copied from parent.  Needed to avoid breaking exclusive property.
 3) [Dinakar Guniguntala <dino@in.ibm.com>] Finish initializing top
    cpuset from cpu_possible_map after smp_init() called.
 4) [Paul Jackson <pj@sgi.com>] Check on each call to __alloc_pages()
    if the current tasks cpuset mems_allowed has changed.  Use a cpuset
    generation number, bumped on any cpuset memory placement change,
    to make this check efficient.  Update the tasks mems_allowed from
    its cpuset, if the cpuset has changed.
 5) [Paul Jackson <pj@sgi.com>] If a task is moved to another cpuset,
    then update its cpus_allowed, using set_cpus_allowed().
 6) [Paul Jackson <pj@sgi.com>] Update Documentation/cpusets.txt to
    reflect above changes (4) and (5).

I continue to recommend the following patch for inclusion in your 2.6.9-*mm
series, when that opens.  It provides an important facility for high
performance computing on large systems.  Simon Derr of Bull (France) and
myself are the primary authors.  Erich Focht has indicated that NEC is also
a potential user of this patch on the TX-7 NUMA machines, and that he
"would very much welcome the inclusion of cpusets."

I offer this update to lkml, in order to invite continued feedback.

The one prerequiste patch for this cpuset patch was just posted before this
one.  That was a patch to provide a new bitmap list format, of which
cpusets is the first user.

This patch has been built on top of 2.6.8.1-mm1, for the arch's:

  i386 x86_64 sparc ia64 powerpc-405 powerpc-750 sparc64

with and without CONFIG_CPUSET.  It has been booted and tested on ia64
(sn2_defconfig, SN2 hardware).  The 'alpha' arch also built, except for
what seems to be an unrelated toolchain problem (crosstool ld sigsegv) in
the final link step.

===

Cpusets provide a mechanism for assigning a set of CPUs and Memory Nodes to
a set of tasks.

Cpusets constrain the CPU and Memory placement of tasks to only the
processor and memory resources within a tasks current cpuset.  They form a
nested hierarchy visible in a virtual file system.  These are the essential
hooks, beyond what is already present, required to manage dynamic job
placement on large systems.

Cpusets require small kernel hooks in init, exit, fork, mempolicy,
sched_setaffinity, page_alloc and vmscan.  And they require a "struct
cpuset" pointer, a cpuset_mems_generation, and a "mems_allowed" nodemask_t
(to go along with the "cpus_allowed" cpumask_t that's already there) in
each task struct.

These hooks:
  1) establish and propagate cpusets,
  2) enforce CPU placement in sched_setaffinity,
  3) enforce Memory placement in mbind and sys_set_mempolicy,
  4) restrict page allocation and scanning to mems_allowed, and
  5) restrict migration and set_cpus_allowed to cpus_allowed.

The other required hook, restricting task scheduling to CPUs in a tasks
cpus_allowed mask, is already present.

Cpusets extend the usefulness of, the existing placement support that was
added to Linux 2.6 kernels: sched_setaffinity() for CPU placement, and
mbind() and set_mempolicy() for memory placement.  On smaller or dedicated
use systems, the existing calls are often sufficient.

On larger NUMA systems, running more than one, performance critical, job,
it is necessary to be able to manage jobs in their entirety.  This includes
providing a job with exclusive CPU and memory that no other job can use,
and being able to list all tasks currently in a cpuset.

A given job running within a cpuset, would likely use the existing
placement calls to manage its CPU and memory placement in more detail.

Cpusets are named, nested sets of CPUs and Memory Nodes.  Each cpuset is
represented by a directory in the cpuset virtual file system, normally
mounted at /dev/cpuset.

Each cpuset directory provides the following files, which can be
read and written:

  cpus:
      List of CPUs allowed to tasks in that cpuset.

  mems:
      List of Memory Nodes allowed to tasks in that cpuset.

  tasks:
      List of pid's of tasks in that cpuset.

  cpu_exclusive:
      Flag (0 or 1) - if set, cpuset has exclusive use of
      its CPUs (no sibling or cousin cpuset may overlap CPUs).

  mem_exclusive:
      Flag (0 or 1) - if set, cpuset has exclusive use of
      its Memory Nodes (no sibling or cousin may overlap).

  notify_on_release:
      Flag (0 or 1) - if set, then /sbin/cpuset_release_agent
      will be invoked, with the name (/dev/cpuset relative path)
      of that cpuset in argv[1], when the last user of it (task
      or child cpuset) goes away.  This supports automatic
      cleanup of abandoned cpusets.

In addition one new filetype is added to the /proc file system:

  /proc/<pid>/cpuset:
      For each task (pid), list its cpuset path, relative to the
      root of the cpuset file system.  This file is read-only.

New cpusets are created using 'mkdir' (at the shell or in C).  Old ones are
removed using 'rmdir'.  The above files are accessed using read(2) and
write(2) system calls, or shell commands such as 'cat' and 'echo'.

The CPUs and Memory Nodes in a given cpuset are always a subset of its
parent.  The root cpuset has all possible CPUs and Memory Nodes in the
system.  A cpuset may be exclusive (cpu or memory) only if its parent is
similarly exclusive.

See further Documentation/cpusets.txt, at the top of the following
patch.


/proc interface:

It is useful, when learning and making new uses of cpusets and placement to be
able to see what are the current value of a tasks cpus_allowed and
mems_allowed, which are the actual placement used by the kernel scheduler and
memory allocator.

The cpus_allowed and mems_allowed values are needed by user space apps that
are micromanaging placement, such as when moving an app to a obtained by
that app within its cpuset using sched_setaffinity, mbind and
set_mempolicy.

The cpus_allowed value is also available via the sched_getaffinity system
call.  But since the entire rest of the cpuset API, including the display
of mems_allowed added here, is via an ascii style presentation in /proc and
/dev/cpuset, it is worth the extra couple lines of code to display
cpus_allowed in the same way.

This patch adds the display of these two fields to the 'status' file in the
/proc/<pid> directory of each task.  The fields are only added if
CONFIG_CPUSETS is enabled (which is also needed to define the mems_allowed
field of each task).  The new output lines look like:

  $ tail -2 /proc/1/status
  Cpus_allowed:   ffffffff,ffffffff,ffffffff,ffffffff
  Mems_allowed:   ffffffff,ffffffff
Signed-off-by: default avatarDinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: default avatarPaul Jackson <pj@sgi.com>
Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarSimon Derr <simon.derr@bull.net>
Signed-off-by: default avatarMatt Mackall <mpm@selenic.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 794c8de9
Hide whitespace changes
Inline Side-by-side
Showing with 2104 additions and 4 deletions
Documentation/cpusets.txt 0 → 100644
View file @ 3a978e55
CPUSETS
-------
Copyright (C) 2004 BULL SA.
Written by Simon.Derr@bull.net
Portions Copyright (c) 2004 Silicon Graphics, Inc.
Modified by Paul Jackson <pj@sgi.com>
CONTENTS:
=========
1. Cpusets
1.1 What are cpusets ?
1.2 Why are cpusets needed ?
1.3 How are cpusets implemented ?
1.4 How do I use cpusets ?
2. Usage Examples and Syntax
2.1 Basic Usage
2.2 Adding/removing cpus
2.3 Setting flags
2.4 Attaching processes
3. Questions
4. Contact
1. Cpusets
==========
1.1 What are cpusets ?
----------------------
Cpusets provide a mechanism for assigning a set of CPUs and Memory
Nodes to a set of tasks.
Cpusets constrain the CPU and Memory placement of tasks to only
the resources within a tasks current cpuset. They form a nested
hierarchy visible in a virtual file system. These are the essential
hooks, beyond what is already present, required to manage dynamic
job placement on large systems.
Each task has a pointer to a cpuset. Multiple tasks may reference
the same cpuset. Requests by a task, using the sched_setaffinity(2)
system call to include CPUs in its CPU affinity mask, and using the
mbind(2) and set_mempolicy(2) system calls to include Memory Nodes
in its memory policy, are both filtered through that tasks cpuset,
filtering out any CPUs or Memory Nodes not in that cpuset. The
scheduler will not schedule a task on a CPU that is not allowed in
its cpus_allowed vector, and the kernel page allocator will not
allocate a page on a node that is not allowed in the requesting tasks
mems_allowed vector.
If a cpuset is cpu or mem exclusive, no other cpuset, other than a direct
ancestor or descendent, may share any of the same CPUs or Memory Nodes.
User level code may create and destroy cpusets by name in the cpuset
virtual file system, manage the attributes and permissions of these
cpusets and which CPUs and Memory Nodes are assigned to each cpuset,
specify and query to which cpuset a task is assigned, and list the
task pids assigned to a cpuset.
1.2 Why are cpusets needed ?
----------------------------
The management of large computer systems, with many processors (CPUs),
complex memory cache hierarchies and multiple Memory Nodes having
non-uniform access times (NUMA) presents additional challenges for
the efficient scheduling and memory placement of processes.
Frequently more modest sized systems can be operated with adequate
efficiency just by letting the operating system automatically share
the available CPU and Memory resources amongst the requesting tasks.
But larger systems, which benefit more from careful processor and
memory placement to reduce memory access times and contention,
and which typically represent a larger investment for the customer,
can benefit from explictly placing jobs on properly sized subsets of
the system.
This can be especially valuable on:
* Web Servers running multiple instances of the same web application,
* Servers running different applications (for instance, a web server
and a database), or
* NUMA systems running large HPC applications with demanding
performance characteristics.
These subsets, or "soft partitions" must be able to be dynamically
adjusted, as the job mix changes, without impacting other concurrently
executing jobs.
The kernel cpuset patch provides the minimum essential kernel
mechanisms required to efficiently implement such subsets. It
leverages existing CPU and Memory Placement facilities in the Linux
kernel to avoid any additional impact on the critical scheduler or
memory allocator code.
1.3 How are cpusets implemented ?
---------------------------------
Cpusets provide a Linux kernel (2.6.7 and above) mechanism to constrain
which CPUs and Memory Nodes are used by a process or set of processes.
The Linux kernel already has a pair of mechanisms to specify on which
CPUs a task may be scheduled (sched_setaffinity) and on which Memory
Nodes it may obtain memory (mbind, set_mempolicy).
Cpusets extends these two mechanisms as follows:
- Cpusets are sets of allowed CPUs and Memory Nodes, known to the
kernel.
- Each task in the system is attached to a cpuset, via a pointer
in the task structure to a reference counted cpuset structure.
- Calls to sched_setaffinity are filtered to just those CPUs
allowed in that tasks cpuset.
- Calls to mbind and set_mempolicy are filtered to just
those Memory Nodes allowed in that tasks cpuset.
- The root cpuset contains all the systems CPUs and Memory
Nodes.
- For any cpuset, one can define child cpusets containing a subset
of the parents CPU and Memory Node resources.
- The hierarchy of cpusets can be mounted at /dev/cpuset, for
browsing and manipulation from user space.
- A cpuset may be marked exclusive, which ensures that no other
cpuset (except direct ancestors and descendents) may contain
any overlapping CPUs or Memory Nodes.
- You can list all the tasks (by pid) attached to any cpuset.
The implementation of cpusets requires a few, simple hooks
into the rest of the kernel, none in performance critical paths:
- in main/init.c, to initialize the root cpuset at system boot.
- in fork and exit, to attach and detach a task from its cpuset.
- in sched_setaffinity, to mask the requested CPUs by what's
allowed in that tasks cpuset.
- in sched.c migrate_all_tasks(), to keep migrating tasks within
the CPUs allowed by their cpuset, if possible.
- in the mbind and set_mempolicy system calls, to mask the requested
Memory Nodes by what's allowed in that tasks cpuset.
- in page_alloc, to restrict memory to allowed nodes.
- in vmscan.c, to restrict page recovery to the current cpuset.
In addition a new file system, of type "cpuset" may be mounted,
typically at /dev/cpuset, to enable browsing and modifying the cpusets
presently known to the kernel. No new system calls are added for
cpusets - all support for querying and modifying cpusets is via
this cpuset file system.
Each task under /proc has an added file named 'cpuset', displaying
the cpuset name, as the path relative to the root of the cpuset file
system.
The /proc/<pid>/status file for each task has two added lines,
displaying the tasks cpus_allowed (on which CPUs it may be scheduled)
and mems_allowed (on which Memory Nodes it may obtain memory),
in the format seen in the following example:
Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff
Mems_allowed: ffffffff,ffffffff
Each cpuset is represented by a directory in the cpuset file system
containing the following files describing that cpuset:
- cpus: list of CPUs in that cpuset
- mems: list of Memory Nodes in that cpuset
- cpu_exclusive flag: is cpu placement exclusive?
- mem_exclusive flag: is memory placement exclusive?
- tasks: list of tasks (by pid) attached to that cpuset
New cpusets are created using the mkdir system call or shell
command. The properties of a cpuset, such as its flags, allowed
CPUs and Memory Nodes, and attached tasks, are modified by writing
to the appropriate file in that cpusets directory, as listed above.
The named hierarchical structure of nested cpusets allows partitioning
a large system into nested, dynamically changeable, "soft-partitions".
The attachment of each task, automatically inherited at fork by any
children of that task, to a cpuset allows organizing the work load
on a system into related sets of tasks such that each set is constrained
to using the CPUs and Memory Nodes of a particular cpuset. A task
may be re-attached to any other cpuset, if allowed by the permissions
on the necessary cpuset file system directories.
Such management of a system "in the large" integrates smoothly with
the detailed placement done on individual tasks and memory regions
using the sched_setaffinity, mbind and set_mempolicy system calls.
The following rules apply to each cpuset:
- Its CPUs and Memory Nodes must be a subset of its parents.
- It can only be marked exclusive if its parent is.
- If its cpu or memory is exclusive, they may not overlap any sibling.
These rules, and the natural hierarchy of cpusets, enable efficient
enforcement of the exclusive guarantee, without having to scan all
cpusets every time any of them change to ensure nothing overlaps a
exclusive cpuset. Also, the use of a Linux virtual file system (vfs)
to represent the cpuset hierarchy provides for a familiar permission
and name space for cpusets, with a minimum of additional kernel code.
1.4 How do I use cpusets ?
--------------------------
In order to minimize the impact of cpusets on critical kernel
code, such as the scheduler, and due to the fact that the kernel
does not support one task updating the memory placement of another
task directly, the impact on a task of changing its cpuset CPU
or Memory Node placement, or of changing to which cpuset a task
is attached, is subtle.
If a cpuset has its Memory Nodes modified, then for each task attached
to that cpuset, the next time that the kernel attempts to allocate
a page of memory for that task, the kernel will notice the change
in the tasks cpuset, and update its per-task memory placement to
remain within the new cpusets memory placement. If the task was using
mempolicy MPOL_BIND, and the nodes to which it was bound overlap with
its new cpuset, then the task will continue to use whatever subset
of MPOL_BIND nodes are still allowed in the new cpuset. If the task
was using MPOL_BIND and now none of its MPOL_BIND nodes are allowed
in the new cpuset, then the task will be essentially treated as if it
was MPOL_BIND bound to the new cpuset (even though its numa placement,
as queried by get_mempolicy(), doesn't change). If a task is moved
from one cpuset to another, then the kernel will adjust the tasks
memory placement, as above, the next time that the kernel attempts
to allocate a page of memory for that task.
If a cpuset has its CPUs modified, then each task using that
cpuset does _not_ change its behavior automatically. In order to
minimize the impact on the critical scheduling code in the kernel,
tasks will continue to use their prior CPU placement until they
are rebound to their cpuset, by rewriting their pid to the 'tasks'
file of their cpuset. If a task had been bound to some subset of its
cpuset using the sched_setaffinity() call, and if any of that subset
is still allowed in its new cpuset settings, then the task will be
restricted to the intersection of the CPUs it was allowed on before,
and its new cpuset CPU placement. If, on the other hand, there is
no overlap between a tasks prior placement and its new cpuset CPU
placement, then the task will be allowed to run on any CPU allowed
in its new cpuset. If a task is moved from one cpuset to another,
its CPU placement is updated in the same way as if the tasks pid is
rewritten to the 'tasks' file of its current cpuset.
In summary, the memory placement of a task whose cpuset is changed is
updated by the kernel, on the next allocation of a page for that task,
but the processor placement is not updated, until that tasks pid is
rewritten to the 'tasks' file of its cpuset. This is done to avoid
impacting the scheduler code in the kernel with a check for changes
in a tasks processor placement.
There is an exception to the above. If hotplug funtionality is used
to remove all the CPUs that are currently assigned to a cpuset,
then the kernel will automatically update the cpus_allowed of all
tasks attached to CPUs in that cpuset with the online CPUs of the
nearest parent cpuset that still has some CPUs online. When memory
hotplug functionality for removing Memory Nodes is available, a
similar exception is expected to apply there as well. In general,
the kernel prefers to violate cpuset placement, over starving a task
that has had all its allowed CPUs or Memory Nodes taken offline. User
code should reconfigure cpusets to only refer to online CPUs and Memory
Nodes when using hotplug to add or remove such resources.
To start a new job that is to be contained within a cpuset, the steps are:
1) mkdir /dev/cpuset
2) mount -t cpuset none /dev/cpuset
3) Create the new cpuset by doing mkdir's and write's (or echo's) in
the /dev/cpuset virtual file system.
4) Start a task that will be the "founding father" of the new job.
5) Attach that task to the new cpuset by writing its pid to the
/dev/cpuset tasks file for that cpuset.
6) fork, exec or clone the job tasks from this founding father task.
For example, the following sequence of commands will setup a cpuset
named "Charlie", containing just CPUs 2 and 3, and Memory Node 1,
and then start a subshell 'sh' in that cpuset:
mount -t cpuset none /dev/cpuset
cd /dev/cpuset
mkdir Charlie
cd Charlie
/bin/echo 2-3 > cpus
/bin/echo 1 > mems
/bin/echo $$ > tasks
sh
# The subshell 'sh' is now running in cpuset Charlie
# The next line should display '/Charlie'
cat /proc/self/cpuset
In the case that a change of cpuset includes wanting to move already
allocated memory pages, consider further the work of IWAMOTO
Toshihiro <iwamoto@valinux.co.jp> for page remapping and memory
hotremoval, which can be found at:
http://people.valinux.co.jp/~iwamoto/mh.html
The integration of cpusets with such memory migration is not yet
available.
In the future, a C library interface to cpusets will likely be
available. For now, the only way to query or modify cpusets is
via the cpuset file system, using the various cd, mkdir, echo, cat,
rmdir commands from the shell, or their equivalent from C.
The sched_setaffinity calls can also be done at the shell prompt using
SGI's runon or Robert Love's taskset. The mbind and set_mempolicy
calls can be done at the shell prompt using the numactl command
(part of Andi Kleen's numa package).
2. Usage Examples and Syntax
============================
2.1 Basic Usage
---------------
Creating, modifying, using the cpusets can be done through the cpuset
virtual filesystem.
To mount it, type:
# mount -t cpuset none /dev/cpuset
Then under /dev/cpuset you can find a tree that corresponds to the
tree of the cpusets in the system. For instance, /dev/cpuset
is the cpuset that holds the whole system.
If you want to create a new cpuset under /dev/cpuset:
# cd /dev/cpuset
# mkdir my_cpuset
Now you want to do something with this cpuset.
# cd my_cpuset
In this directory you can find several files:
# ls
cpus cpu_exclusive mems mem_exclusive tasks
Reading them will give you information about the state of this cpuset:
the CPUs and Memory Nodes it can use, the processes that are using
it, its properties. By writing to these files you can manipulate
the cpuset.
Set some flags:
# /bin/echo 1 > cpu_exclusive
Add some cpus:
# /bin/echo 0-7 > cpus
Now attach your shell to this cpuset:
# /bin/echo $$ > tasks
You can also create cpusets inside your cpuset by using mkdir in this
directory.
# mkdir my_sub_cs
To remove a cpuset, just use rmdir:
# rmdir my_sub_cs
This will fail if the cpuset is in use (has cpusets inside, or has
processes attached).
2.2 Adding/removing cpus
------------------------
This is the syntax to use when writing in the cpus or mems files
in cpuset directories:
# /bin/echo 1-4 > cpus -> set cpus list to cpus 1,2,3,4
# /bin/echo 1,2,3,4 > cpus -> set cpus list to cpus 1,2,3,4
2.3 Setting flags
-----------------
The syntax is very simple:
# /bin/echo 1 > cpu_exclusive -> set flag 'cpu_exclusive'
# /bin/echo 0 > cpu_exclusive -> unset flag 'cpu_exclusive'
2.4 Attaching processes
-----------------------
# /bin/echo PID > tasks
Note that it is PID, not PIDs. You can only attach ONE task at a time.
If you have several tasks to attach, you have to do it one after another:
# /bin/echo PID1 > tasks
# /bin/echo PID2 > tasks
...
# /bin/echo PIDn > tasks
3. Questions
============
Q: what's up with this '/bin/echo' ?
A: bash's builtin 'echo' command does not check calls to write() against
errors. If you use it in the cpuset file system, you won't be
able to tell whether a command succeeded or failed.
Q: When I attach processes, only the first of the line gets really attached !
A: We can only return one error code per call to write(). So you should also
put only ONE pid.
4. Contact
==========
Web: http://www.bullopensource.org/cpuset
fs/proc/array.c
View file @ 3a978e55
......@@ -73,6 +73,7 @@
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/times.h>
#include <linux/cpuset.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
......@@ -300,6 +301,7 @@ int proc_pid_status(struct task_struct *task, char * buffer)
}
buffer = task_sig(task, buffer);
buffer = task_cap(task, buffer);
buffer = cpuset_task_status_allowed(task, buffer);
#if defined(CONFIG_ARCH_S390)
buffer = task_show_regs(task, buffer);
#endif
......
fs/proc/base.c
View file @ 3a978e55
......@@ -33,6 +33,7 @@
#include <linux/security.h>
#include <linux/ptrace.h>
#include <linux/seccomp.h>
#include <linux/cpuset.h>
#include "internal.h"
/*
......@@ -68,6 +69,9 @@ enum pid_directory_inos {
#ifdef CONFIG_SCHEDSTATS
PROC_TGID_SCHEDSTAT,
#endif
#ifdef CONFIG_CPUSETS
PROC_TGID_CPUSET,
#endif
#ifdef CONFIG_SECURITY
PROC_TGID_ATTR,
PROC_TGID_ATTR_CURRENT,
......@@ -102,6 +106,9 @@ enum pid_directory_inos {
#ifdef CONFIG_SCHEDSTATS
PROC_TID_SCHEDSTAT,
#endif
#ifdef CONFIG_CPUSETS
PROC_TID_CPUSET,
#endif
#ifdef CONFIG_SECURITY
PROC_TID_ATTR,
PROC_TID_ATTR_CURRENT,
......@@ -152,6 +159,9 @@ static struct pid_entry tgid_base_stuff[] = {
#endif
#ifdef CONFIG_SCHEDSTATS
E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_CPUSETS
E(PROC_TGID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
#endif
E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
......@@ -185,6 +195,9 @@ static struct pid_entry tid_base_stuff[] = {
#endif
#ifdef CONFIG_SCHEDSTATS
E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_CPUSETS
E(PROC_TID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
#endif
E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
......@@ -1556,6 +1569,12 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
inode->i_fop = &proc_info_file_operations;
ei->op.proc_read = proc_pid_schedstat;
break;
#endif
#ifdef CONFIG_CPUSETS
case PROC_TID_CPUSET:
case PROC_TGID_CPUSET:
inode->i_fop = &proc_cpuset_operations;
break;
#endif
case PROC_TID_OOM_SCORE:
case PROC_TGID_OOM_SCORE:
......
include/linux/cpuset.h 0 → 100644
View file @ 3a978e55
#ifndef _LINUX_CPUSET_H
#define _LINUX_CPUSET_H
/*
* cpuset interface
*
* Copyright (C) 2003 BULL SA
* Copyright (C) 2004 Silicon Graphics, Inc.
*
*/
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
#ifdef CONFIG_CPUSETS
extern int cpuset_init(void);
extern void cpuset_init_smp(void);
extern void cpuset_fork(struct task_struct *p);
extern void cpuset_exit(struct task_struct *p);
extern const cpumask_t cpuset_cpus_allowed(const struct task_struct *p);
void cpuset_init_current_mems_allowed(void);
void cpuset_update_current_mems_allowed(void);
void cpuset_restrict_to_mems_allowed(unsigned long *nodes);
int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl);
int cpuset_zone_allowed(struct zone *z);
extern struct file_operations proc_cpuset_operations;
extern char *cpuset_task_status_allowed(struct task_struct *task, char *buffer);
#else /* !CONFIG_CPUSETS */
static inline int cpuset_init(void) { return 0; }
static inline void cpuset_init_smp(void) {}
static inline void cpuset_fork(struct task_struct *p) {}
static inline void cpuset_exit(struct task_struct *p) {}
static inline const cpumask_t cpuset_cpus_allowed(struct task_struct *p)
{
return cpu_possible_map;
}
static inline void cpuset_init_current_mems_allowed(void) {}
static inline void cpuset_update_current_mems_allowed(void) {}
static inline void cpuset_restrict_to_mems_allowed(unsigned long *nodes) {}
static inline int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
{
return 1;
}
static inline int cpuset_zone_allowed(struct zone *z)
{
return 1;
}
static inline char *cpuset_task_status_allowed(struct task_struct *task,
char *buffer)
{
return buffer;
}
#endif /* !CONFIG_CPUSETS */
#endif /* _LINUX_CPUSET_H */
include/linux/sched.h
View file @ 3a978e55
......@@ -14,6 +14,7 @@
#include <linux/thread_info.h>
#include <linux/cpumask.h>
#include <linux/errno.h>
#include <linux/nodemask.h>
#include <asm/system.h>
#include <asm/semaphore.h>
......@@ -514,6 +515,7 @@ extern void cpu_attach_domain(struct sched_domain *sd, int cpu);
struct io_context; /* See blkdev.h */
void exit_io_context(void);
struct cpuset;
#define NGROUPS_SMALL 32
#define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t)))
......@@ -712,6 +714,11 @@ struct task_struct {
struct mempolicy *mempolicy;
short il_next;
#endif
#ifdef CONFIG_CPUSETS
struct cpuset *cpuset;
nodemask_t mems_allowed;
int cpuset_mems_generation;
#endif
};
static inline pid_t process_group(struct task_struct *tsk)
......
init/Kconfig
View file @ 3a978e55
......@@ -237,6 +237,16 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
config CPUSETS
bool "Cpuset support"
depends on SMP
help
This options will let you create and manage CPUSET's which
allow dynamically partitioning a system into sets of CPUs and
Memory Nodes and assigning tasks to run only within those sets.
This is primarily useful on large SMP or NUMA systems.
Say N if unsure.
menuconfig EMBEDDED
bool "Configure standard kernel features (for small systems)"
......
init/main.c
View file @ 3a978e55
......@@ -41,6 +41,7 @@
#include <linux/kallsyms.h>
#include <linux/writeback.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/efi.h>
#include <linux/unistd.h>
#include <linux/rmap.h>
......@@ -515,6 +516,8 @@ asmlinkage void __init start_kernel(void)
#ifdef CONFIG_PROC_FS
proc_root_init();
#endif
cpuset_init();
check_bugs();
acpi_early_init(); /* before LAPIC and SMP init */
......@@ -656,6 +659,8 @@ static int init(void * unused)
smp_init();
sched_init_smp();
cpuset_init_smp();
/*
* Do this before initcalls, because some drivers want to access
* firmware files.
......
kernel/Makefile
View file @ 3a978e55
......@@ -18,6 +18,7 @@ obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PM) += power/
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_COMPAT) += compat.o
obj-$(CONFIG_CPUSETS) += cpuset.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_IKCONFIG_PROC) += configs.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
......
kernel/cpuset.c 0 → 100644
View file @ 3a978e55
/*
* kernel/cpuset.c
*
* Processor and Memory placement constraints for sets of tasks.
*
* Copyright (C) 2003 BULL SA.
* Copyright (C) 2004 Silicon Graphics, Inc.
*
* Portions derived from Patrick Mochel's sysfs code.
* sysfs is Copyright (c) 2001-3 Patrick Mochel
* Portions Copyright (c) 2004 Silicon Graphics, Inc.
*
* 2003-10-10 Written by Simon Derr <simon.derr@bull.net>
* 2003-10-22 Updates by Stephen Hemminger.
* 2004 May-July Rework by Paul Jackson <pj@sgi.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of the Linux
* distribution for more details.
*/
#include <linux/config.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/cpuset.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/backing-dev.h>
#include <linux/sort.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
#define CPUSET_SUPER_MAGIC 0x27e0eb
struct cpuset {
unsigned long flags; /* "unsigned long" so bitops work */
cpumask_t cpus_allowed; /* CPUs allowed to tasks in cpuset */
nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */
atomic_t count; /* count tasks using this cpuset */
/*
* We link our 'sibling' struct into our parents 'children'.
* Our children link their 'sibling' into our 'children'.
*/
struct list_head sibling; /* my parents children */
struct list_head children; /* my children */
struct cpuset *parent; /* my parent */
struct dentry *dentry; /* cpuset fs entry */
/*
* Copy of global cpuset_mems_generation as of the most
* recent time this cpuset changed its mems_allowed.
*/
int mems_generation;
};
/* bits in struct cpuset flags field */
typedef enum {
CS_CPU_EXCLUSIVE,
CS_MEM_EXCLUSIVE,
CS_REMOVED,
CS_NOTIFY_ON_RELEASE
} cpuset_flagbits_t;
/* convenient tests for these bits */
static inline int is_cpu_exclusive(const struct cpuset *cs)
{
return !!test_bit(CS_CPU_EXCLUSIVE, &cs->flags);
}
static inline int is_mem_exclusive(const struct cpuset *cs)
{
return !!test_bit(CS_MEM_EXCLUSIVE, &cs->flags);
}
static inline int is_removed(const struct cpuset *cs)
{
return !!test_bit(CS_REMOVED, &cs->flags);
}
static inline int notify_on_release(const struct cpuset *cs)
{
return !!test_bit(CS_NOTIFY_ON_RELEASE, &cs->flags);
}
/*
* Increment this atomic integer everytime any cpuset changes its
* mems_allowed value. Users of cpusets can track this generation
* number, and avoid having to lock and reload mems_allowed unless
* the cpuset they're using changes generation.
*
* A single, global generation is needed because attach_task() could
* reattach a task to a different cpuset, which must not have its
* generation numbers aliased with those of that tasks previous cpuset.
*
* Generations are needed for mems_allowed because one task cannot
* modify anothers memory placement. So we must enable every task,
* on every visit to __alloc_pages(), to efficiently check whether
* its current->cpuset->mems_allowed has changed, requiring an update
* of its current->mems_allowed.
*/
static atomic_t cpuset_mems_generation = ATOMIC_INIT(1);
static struct cpuset top_cpuset = {
.flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)),
.cpus_allowed = CPU_MASK_ALL,
.mems_allowed = NODE_MASK_ALL,
.count = ATOMIC_INIT(0),
.sibling = LIST_HEAD_INIT(top_cpuset.sibling),
.children = LIST_HEAD_INIT(top_cpuset.children),
.parent = NULL,
.dentry = NULL,
.mems_generation = 0,
};
static struct vfsmount *cpuset_mount;
static struct super_block *cpuset_sb = NULL;
/*
* cpuset_sem should be held by anyone who is depending on the children
* or sibling lists of any cpuset, or performing non-atomic operations
* on the flags or *_allowed values of a cpuset, such as raising the
* CS_REMOVED flag bit iff it is not already raised, or reading and
* conditionally modifying the *_allowed values. One kernel global
* cpuset semaphore should be sufficient - these things don't change
* that much.
*
* The code that modifies cpusets holds cpuset_sem across the entire
* operation, from cpuset_common_file_write() down, single threading
* all cpuset modifications (except for counter manipulations from
* fork and exit) across the system. This presumes that cpuset
* modifications are rare - better kept simple and safe, even if slow.
*
* The code that reads cpusets, such as in cpuset_common_file_read()
* and below, only holds cpuset_sem across small pieces of code, such
* as when reading out possibly multi-word cpumasks and nodemasks, as
* the risks are less, and the desire for performance a little greater.
* The proc_cpuset_show() routine needs to hold cpuset_sem to insure
* that no cs->dentry is NULL, as it walks up the cpuset tree to root.
*
* The hooks from fork and exit, cpuset_fork() and cpuset_exit(), don't
* (usually) grab cpuset_sem. These are the two most performance
* critical pieces of code here. The exception occurs on exit(),
* if the last task using a cpuset exits, and the cpuset was marked
* notify_on_release. In that case, the cpuset_sem is taken, the
* path to the released cpuset calculated, and a usermode call made
* to /sbin/cpuset_release_agent with the name of the cpuset (path
* relative to the root of cpuset file system) as the argument.
*
* A cpuset can only be deleted if both its 'count' of using tasks is
* zero, and its list of 'children' cpusets is empty. Since all tasks
* in the system use _some_ cpuset, and since there is always at least
* one task in the system (init, pid == 1), therefore, top_cpuset
* always has either children cpusets and/or using tasks. So no need
* for any special hack to ensure that top_cpuset cannot be deleted.
*/
static DECLARE_MUTEX(cpuset_sem);
/*
* A couple of forward declarations required, due to cyclic reference loop:
* cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file
* -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir.
*/
static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode);
static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry);
static struct backing_dev_info cpuset_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.memory_backed = 1, /* Does not contribute to dirty memory */
};
static struct inode *cpuset_new_inode(mode_t mode)
{
struct inode *inode = new_inode(cpuset_sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_mapping->backing_dev_info = &cpuset_backing_dev_info;
}
return inode;
}
static void cpuset_diput(struct dentry *dentry, struct inode *inode)
{
/* is dentry a directory ? if so, kfree() associated cpuset */
if (S_ISDIR(inode->i_mode)) {
struct cpuset *cs = dentry->d_fsdata;
BUG_ON(!(is_removed(cs)));
kfree(cs);
}
iput(inode);
}
static struct dentry_operations cpuset_dops = {
.d_iput = cpuset_diput,
};
static struct dentry *cpuset_get_dentry(struct dentry *parent, const char *name)
{
struct qstr qstr;
struct dentry *d;
qstr.name = name;
qstr.len = strlen(name);
qstr.hash = full_name_hash(name, qstr.len);
d = lookup_hash(&qstr, parent);
if (!IS_ERR(d))
d->d_op = &cpuset_dops;
return d;
}
static void remove_dir(struct dentry *d)
{
struct dentry *parent = dget(d->d_parent);
d_delete(d);
simple_rmdir(parent->d_inode, d);
dput(parent);
}
/*
* NOTE : the dentry must have been dget()'ed
*/
static void cpuset_d_remove_dir(struct dentry *dentry)
{
struct list_head *node;
spin_lock(&dcache_lock);
node = dentry->d_subdirs.next;
while (node != &dentry->d_subdirs) {
struct dentry *d = list_entry(node, struct dentry, d_child);
list_del_init(node);
if (d->d_inode) {
d = dget_locked(d);
spin_unlock(&dcache_lock);
d_delete(d);
simple_unlink(dentry->d_inode, d);
dput(d);
spin_lock(&dcache_lock);
}
node = dentry->d_subdirs.next;
}
list_del_init(&dentry->d_child);
spin_unlock(&dcache_lock);
remove_dir(dentry);
}
static struct super_operations cpuset_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static int cpuset_fill_super(struct super_block *sb, void *unused_data,
int unused_silent)
{
struct inode *inode;
struct dentry *root;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = CPUSET_SUPER_MAGIC;
sb->s_op = &cpuset_ops;
cpuset_sb = sb;
inode = cpuset_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR);
if (inode) {
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directories start off with i_nlink == 2 (for "." entry) */
inode->i_nlink++;
} else {
return -ENOMEM;
}
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
sb->s_root = root;
return 0;
}
static struct super_block *cpuset_get_sb(struct file_system_type *fs_type,
int flags, const char *unused_dev_name,
void *data)
{
return get_sb_single(fs_type, flags, data, cpuset_fill_super);
}
static struct file_system_type cpuset_fs_type = {
.name = "cpuset",
.get_sb = cpuset_get_sb,
.kill_sb = kill_litter_super,
};
/* struct cftype:
*
* The files in the cpuset filesystem mostly have a very simple read/write
* handling, some common function will take care of it. Nevertheless some cases
* (read tasks) are special and therefore I define this structure for every
* kind of file.
*
*
* When reading/writing to a file:
* - the cpuset to use in file->f_dentry->d_parent->d_fsdata
* - the 'cftype' of the file is file->f_dentry->d_fsdata
*/
struct cftype {
char *name;
int private;
int (*open) (struct inode *inode, struct file *file);
ssize_t (*read) (struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos);
int (*write) (struct file *file, const char *buf, size_t nbytes,
loff_t *ppos);
int (*release) (struct inode *inode, struct file *file);
};
static inline struct cpuset *__d_cs(struct dentry *dentry)
{
return dentry->d_fsdata;
}
static inline struct cftype *__d_cft(struct dentry *dentry)
{
return dentry->d_fsdata;
}
/*
* Call with cpuset_sem held. Writes path of cpuset into buf.
* Returns 0 on success, -errno on error.
*/
static int cpuset_path(const struct cpuset *cs, char *buf, int buflen)
{
char *start;
start = buf + buflen;
*--start = '\0';
for (;;) {
int len = cs->dentry->d_name.len;
if ((start -= len) < buf)
return -ENAMETOOLONG;
memcpy(start, cs->dentry->d_name.name, len);
cs = cs->parent;
if (!cs)
break;
if (!cs->parent)
continue;
if (--start < buf)
return -ENAMETOOLONG;
*start = '/';
}
memmove(buf, start, buf + buflen - start);
return 0;
}
/*
* Notify userspace when a cpuset is released, by running
* /sbin/cpuset_release_agent with the name of the cpuset (path
* relative to the root of cpuset file system) as the argument.
*
* Most likely, this user command will try to rmdir this cpuset.
*
* This races with the possibility that some other task will be
* attached to this cpuset before it is removed, or that some other
* user task will 'mkdir' a child cpuset of this cpuset. That's ok.
* The presumed 'rmdir' will fail quietly if this cpuset is no longer
* unused, and this cpuset will be reprieved from its death sentence,
* to continue to serve a useful existence. Next time it's released,
* we will get notified again, if it still has 'notify_on_release' set.
*
* Note final arg to call_usermodehelper() is 0 - that means
* don't wait. Since we are holding the global cpuset_sem here,
* and we are asking another thread (started from keventd) to rmdir a
* cpuset, we can't wait - or we'd deadlock with the removing thread
* on cpuset_sem.
*/
static int cpuset_release_agent(char *cpuset_str)
{
char *argv[3], *envp[3];
int i;
i = 0;
argv[i++] = "/sbin/cpuset_release_agent";
argv[i++] = cpuset_str;
argv[i] = NULL;
i = 0;
/* minimal command environment */
envp[i++] = "HOME=/";
envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
envp[i] = NULL;
return call_usermodehelper(argv[0], argv, envp, 0);
}
/*
* Either cs->count of using tasks transitioned to zero, or the
* cs->children list of child cpusets just became empty. If this
* cs is notify_on_release() and now both the user count is zero and
* the list of children is empty, send notice to user land.
*/
static void check_for_release(struct cpuset *cs)
{
if (notify_on_release(cs) && atomic_read(&cs->count) == 0 &&
list_empty(&cs->children)) {
char *buf;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buf)
return;
if (cpuset_path(cs, buf, PAGE_SIZE) < 0)
goto out;
cpuset_release_agent(buf);
out:
kfree(buf);
}
}
/*
* Return in *pmask the portion of a cpusets's cpus_allowed that
* are online. If none are online, walk up the cpuset hierarchy
* until we find one that does have some online cpus. If we get
* all the way to the top and still haven't found any online cpus,
* return cpu_online_map. Or if passed a NULL cs from an exit'ing
* task, return cpu_online_map.
*
* One way or another, we guarantee to return some non-empty subset
* of cpu_online_map.
*
* Call with cpuset_sem held.
*/
static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask)
{
while (cs && !cpus_intersects(cs->cpus_allowed, cpu_online_map))
cs = cs->parent;
if (cs)
cpus_and(*pmask, cs->cpus_allowed, cpu_online_map);
else
*pmask = cpu_online_map;
BUG_ON(!cpus_intersects(*pmask, cpu_online_map));
}
/*
* Return in *pmask the portion of a cpusets's mems_allowed that
* are online. If none are online, walk up the cpuset hierarchy
* until we find one that does have some online mems. If we get
* all the way to the top and still haven't found any online mems,
* return node_online_map.
*
* One way or another, we guarantee to return some non-empty subset
* of node_online_map.
*
* Call with cpuset_sem held.
*/
static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
{
while (cs && !nodes_intersects(cs->mems_allowed, node_online_map))
cs = cs->parent;
if (cs)
nodes_and(*pmask, cs->mems_allowed, node_online_map);
else
*pmask = node_online_map;
BUG_ON(!nodes_intersects(*pmask, node_online_map));
}
/*
* is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q?
*
* One cpuset is a subset of another if all its allowed CPUs and
* Memory Nodes are a subset of the other, and its exclusive flags
* are only set if the other's are set.
*/
static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
{
return cpus_subset(p->cpus_allowed, q->cpus_allowed) &&
nodes_subset(p->mems_allowed, q->mems_allowed) &&
is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
is_mem_exclusive(p) <= is_mem_exclusive(q);
}
/*
* validate_change() - Used to validate that any proposed cpuset change
* follows the structural rules for cpusets.
*
* If we replaced the flag and mask values of the current cpuset
* (cur) with those values in the trial cpuset (trial), would
* our various subset and exclusive rules still be valid? Presumes
* cpuset_sem held.
*
* 'cur' is the address of an actual, in-use cpuset. Operations
* such as list traversal that depend on the actual address of the
* cpuset in the list must use cur below, not trial.
*
* 'trial' is the address of bulk structure copy of cur, with
* perhaps one or more of the fields cpus_allowed, mems_allowed,
* or flags changed to new, trial values.
*
* Return 0 if valid, -errno if not.
*/
static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
{
struct cpuset *c, *par;
/* Each of our child cpusets must be a subset of us */
list_for_each_entry(c, &cur->children, sibling) {
if (!is_cpuset_subset(c, trial))
return -EBUSY;
}
/* Remaining checks don't apply to root cpuset */
if ((par = cur->parent) == NULL)
return 0;
/* We must be a subset of our parent cpuset */
if (!is_cpuset_subset(trial, par))
return -EACCES;
/* If either I or some sibling (!= me) is exclusive, we can't overlap */
list_for_each_entry(c, &par->children, sibling) {
if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
c != cur &&
cpus_intersects(trial->cpus_allowed, c->cpus_allowed))
return -EINVAL;
if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
c != cur &&
nodes_intersects(trial->mems_allowed, c->mems_allowed))
return -EINVAL;
}
return 0;
}
static int update_cpumask(struct cpuset *cs, char *buf)
{
struct cpuset trialcs;
int retval;
trialcs = *cs;
retval = cpulist_parse(buf, trialcs.cpus_allowed);
if (retval < 0)
return retval;
cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
if (cpus_empty(trialcs.cpus_allowed))
return -ENOSPC;
retval = validate_change(cs, &trialcs);
if (retval == 0)
cs->cpus_allowed = trialcs.cpus_allowed;
return retval;
}
static int update_nodemask(struct cpuset *cs, char *buf)
{
struct cpuset trialcs;
int retval;
trialcs = *cs;
retval = nodelist_parse(buf, trialcs.mems_allowed);
if (retval < 0)
return retval;
nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map);
if (nodes_empty(trialcs.mems_allowed))
return -ENOSPC;
retval = validate_change(cs, &trialcs);
if (retval == 0) {
cs->mems_allowed = trialcs.mems_allowed;
atomic_inc(&cpuset_mems_generation);
cs->mems_generation = atomic_read(&cpuset_mems_generation);
}
return retval;
}
/*
* update_flag - read a 0 or a 1 in a file and update associated flag
* bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
* CS_NOTIFY_ON_RELEASE)
* cs: the cpuset to update
* buf: the buffer where we read the 0 or 1
*/
static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
{
int turning_on;
struct cpuset trialcs;
int err;
turning_on = (simple_strtoul(buf, NULL, 10) != 0);
trialcs = *cs;
if (turning_on)
set_bit(bit, &trialcs.flags);
else
clear_bit(bit, &trialcs.flags);
err = validate_change(cs, &trialcs);
if (err == 0) {
if (turning_on)
set_bit(bit, &cs->flags);
else
clear_bit(bit, &cs->flags);
}
return err;
}
static int attach_task(struct cpuset *cs, char *buf)
{
pid_t pid;
struct task_struct *tsk;
struct cpuset *oldcs;
cpumask_t cpus;
if (sscanf(buf, "%d", &pid) != 1)
return -EIO;
if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
if (pid) {
read_lock(&tasklist_lock);
tsk = find_task_by_pid(pid);
if (!tsk) {
read_unlock(&tasklist_lock);
return -ESRCH;
}
get_task_struct(tsk);
read_unlock(&tasklist_lock);
if ((current->euid) && (current->euid != tsk->uid)
&& (current->euid != tsk->suid)) {
put_task_struct(tsk);
return -EACCES;
}
} else {
tsk = current;
get_task_struct(tsk);
}
task_lock(tsk);
oldcs = tsk->cpuset;
if (!oldcs) {
task_unlock(tsk);
put_task_struct(tsk);
return -ESRCH;
}
atomic_inc(&cs->count);
tsk->cpuset = cs;
task_unlock(tsk);
guarantee_online_cpus(cs, &cpus);
set_cpus_allowed(tsk, cpus);
put_task_struct(tsk);
if (atomic_dec_and_test(&oldcs->count))
check_for_release(oldcs);
return 0;
}
/* The various types of files and directories in a cpuset file system */
typedef enum {
FILE_ROOT,
FILE_DIR,
FILE_CPULIST,
FILE_MEMLIST,
FILE_CPU_EXCLUSIVE,
FILE_MEM_EXCLUSIVE,
FILE_NOTIFY_ON_RELEASE,
FILE_TASKLIST,
} cpuset_filetype_t;
static ssize_t cpuset_common_file_write(struct file *file, const char *userbuf,
size_t nbytes, loff_t *unused_ppos)
{
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
struct cftype *cft = __d_cft(file->f_dentry);
cpuset_filetype_t type = cft->private;
char *buffer;
int retval = 0;
/* Crude upper limit on largest legitimate cpulist user might write. */
if (nbytes > 100 + 6 * NR_CPUS)
return -E2BIG;
/* +1 for nul-terminator */
if ((buffer = kmalloc(nbytes + 1, GFP_KERNEL)) == 0)
return -ENOMEM;
if (copy_from_user(buffer, userbuf, nbytes)) {
retval = -EFAULT;
goto out1;
}
buffer[nbytes] = 0; /* nul-terminate */
down(&cpuset_sem);
if (is_removed(cs)) {
retval = -ENODEV;
goto out2;
}
switch (type) {
case FILE_CPULIST:
retval = update_cpumask(cs, buffer);
break;
case FILE_MEMLIST:
retval = update_nodemask(cs, buffer);
break;
case FILE_CPU_EXCLUSIVE:
retval = update_flag(CS_CPU_EXCLUSIVE, cs, buffer);
break;
case FILE_MEM_EXCLUSIVE:
retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer);
break;
case FILE_NOTIFY_ON_RELEASE:
retval = update_flag(CS_NOTIFY_ON_RELEASE, cs, buffer);
break;
case FILE_TASKLIST:
retval = attach_task(cs, buffer);
break;
default:
retval = -EINVAL;
goto out2;
}
if (retval == 0)
retval = nbytes;
out2:
up(&cpuset_sem);
out1:
kfree(buffer);
return retval;
}
static ssize_t cpuset_file_write(struct file *file, const char *buf,
size_t nbytes, loff_t *ppos)
{
ssize_t retval = 0;
struct cftype *cft = __d_cft(file->f_dentry);
if (!cft)
return -ENODEV;
/* special function ? */
if (cft->write)
retval = cft->write(file, buf, nbytes, ppos);
else
retval = cpuset_common_file_write(file, buf, nbytes, ppos);
return retval;
}
/*
* These ascii lists should be read in a single call, by using a user
* buffer large enough to hold the entire map. If read in smaller
* chunks, there is no guarantee of atomicity. Since the display format
* used, list of ranges of sequential numbers, is variable length,
* and since these maps can change value dynamically, one could read
* gibberish by doing partial reads while a list was changing.
* A single large read to a buffer that crosses a page boundary is
* ok, because the result being copied to user land is not recomputed
* across a page fault.
*/
static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
{
cpumask_t mask;
down(&cpuset_sem);
mask = cs->cpus_allowed;
up(&cpuset_sem);
return cpulist_scnprintf(page, PAGE_SIZE, mask);
}
static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)
{
nodemask_t mask;
down(&cpuset_sem);
mask = cs->mems_allowed;
up(&cpuset_sem);
return nodelist_scnprintf(page, PAGE_SIZE, mask);
}
static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos)
{
struct cftype *cft = __d_cft(file->f_dentry);
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
cpuset_filetype_t type = cft->private;
char *page;
ssize_t retval = 0;
char *s;
char *start;
size_t n;
if (!(page = (char *)__get_free_page(GFP_KERNEL)))
return -ENOMEM;
s = page;
switch (type) {
case FILE_CPULIST:
s += cpuset_sprintf_cpulist(s, cs);
break;
case FILE_MEMLIST:
s += cpuset_sprintf_memlist(s, cs);
break;
case FILE_CPU_EXCLUSIVE:
*s++ = is_cpu_exclusive(cs) ? '1' : '0';
break;
case FILE_MEM_EXCLUSIVE:
*s++ = is_mem_exclusive(cs) ? '1' : '0';
break;
case FILE_NOTIFY_ON_RELEASE:
*s++ = notify_on_release(cs) ? '1' : '0';
break;
default:
retval = -EINVAL;
goto out;
}
*s++ = '\n';
*s = '\0';
start = page + *ppos;
n = s - start;
retval = n - copy_to_user(buf, start, min(n, nbytes));
*ppos += retval;
out:
free_page((unsigned long)page);
return retval;
}
static ssize_t cpuset_file_read(struct file *file, char *buf, size_t nbytes,
loff_t *ppos)
{
ssize_t retval = 0;
struct cftype *cft = __d_cft(file->f_dentry);
if (!cft)
return -ENODEV;
/* special function ? */
if (cft->read)
retval = cft->read(file, buf, nbytes, ppos);
else
retval = cpuset_common_file_read(file, buf, nbytes, ppos);
return retval;
}
static int cpuset_file_open(struct inode *inode, struct file *file)
{
int err;
struct cftype *cft;
err = generic_file_open(inode, file);
if (err)
return err;
cft = __d_cft(file->f_dentry);
if (!cft)
return -ENODEV;
if (cft->open)
err = cft->open(inode, file);
else
err = 0;
return err;
}
static int cpuset_file_release(struct inode *inode, struct file *file)
{
struct cftype *cft = __d_cft(file->f_dentry);
if (cft->release)
return cft->release(inode, file);
return 0;
}
static struct file_operations cpuset_file_operations = {
.read = cpuset_file_read,
.write = cpuset_file_write,
.llseek = generic_file_llseek,
.open = cpuset_file_open,
.release = cpuset_file_release,
};
static struct inode_operations cpuset_dir_inode_operations = {
.lookup = simple_lookup,
.mkdir = cpuset_mkdir,
.rmdir = cpuset_rmdir,
};
static int cpuset_create_file(struct dentry *dentry, int mode)
{
struct inode *inode;
if (!dentry)
return -ENOENT;
if (dentry->d_inode)
return -EEXIST;
inode = cpuset_new_inode(mode);
if (!inode)
return -ENOMEM;
if (S_ISDIR(mode)) {
inode->i_op = &cpuset_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* start off with i_nlink == 2 (for "." entry) */
inode->i_nlink++;
} else if (S_ISREG(mode)) {
inode->i_size = 0;
inode->i_fop = &cpuset_file_operations;
}
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
return 0;
}
/*
* cpuset_create_dir - create a directory for an object.
* cs: the cpuset we create the directory for.
* It must have a valid ->parent field
* And we are going to fill its ->dentry field.
* name: The name to give to the cpuset directory. Will be copied.
* mode: mode to set on new directory.
*/
static int cpuset_create_dir(struct cpuset *cs, const char *name, int mode)
{
struct dentry *dentry = NULL;
struct dentry *parent;
int error = 0;
parent = cs->parent->dentry;
dentry = cpuset_get_dentry(parent, name);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
error = cpuset_create_file(dentry, S_IFDIR | mode);
if (!error) {
dentry->d_fsdata = cs;
parent->d_inode->i_nlink++;
cs->dentry = dentry;
}
dput(dentry);
return error;
}
static int cpuset_add_file(struct dentry *dir, const struct cftype *cft)
{
struct dentry *dentry;
int error;
down(&dir->d_inode->i_sem);
dentry = cpuset_get_dentry(dir, cft->name);
if (!IS_ERR(dentry)) {
error = cpuset_create_file(dentry, 0644 | S_IFREG);
if (!error)
dentry->d_fsdata = (void *)cft;
dput(dentry);
} else
error = PTR_ERR(dentry);
up(&dir->d_inode->i_sem);
return error;
}
/*
* Stuff for reading the 'tasks' file.
*
* Reading this file can return large amounts of data if a cpuset has
* *lots* of attached tasks. So it may need several calls to read(),
* but we cannot guarantee that the information we produce is correct
* unless we produce it entirely atomically.
*
* Upon tasks file open(), a struct ctr_struct is allocated, that
* will have a pointer to an array (also allocated here). The struct
* ctr_struct * is stored in file->private_data. Its resources will
* be freed by release() when the file is closed. The array is used
* to sprintf the PIDs and then used by read().
*/
/* cpusets_tasks_read array */
struct ctr_struct {
char *buf;
int bufsz;
};
/*
* Load into 'pidarray' up to 'npids' of the tasks using cpuset 'cs'.
* Return actual number of pids loaded.
*/
static inline int pid_array_load(pid_t *pidarray, int npids, struct cpuset *cs)
{
int n = 0;
struct task_struct *g, *p;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if (p->cpuset == cs) {
pidarray[n++] = p->pid;
if (unlikely(n == npids))
goto array_full;
}
} while_each_thread(g, p);
array_full:
read_unlock(&tasklist_lock);
return n;
}
static int cmppid(const void *a, const void *b)
{
return *(pid_t *)a - *(pid_t *)b;
}
/*
* Convert array 'a' of 'npids' pid_t's to a string of newline separated
* decimal pids in 'buf'. Don't write more than 'sz' chars, but return
* count 'cnt' of how many chars would be written if buf were large enough.
*/
static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids)
{
int cnt = 0;
int i;
for (i = 0; i < npids; i++)
cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]);
return cnt;
}
static int cpuset_tasks_open(struct inode *unused, struct file *file)
{
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
struct ctr_struct *ctr;
pid_t *pidarray;
int npids;
char c;
if (!(file->f_mode & FMODE_READ))
return 0;
ctr = kmalloc(sizeof(*ctr), GFP_KERNEL);
if (!ctr)
goto err0;
/*
* If cpuset gets more users after we read count, we won't have
* enough space - tough. This race is indistinguishable to the
* caller from the case that the additional cpuset users didn't
* show up until sometime later on.
*/
npids = atomic_read(&cs->count);
pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL);
if (!pidarray)
goto err1;
npids = pid_array_load(pidarray, npids, cs);
sort(pidarray, npids, sizeof(pid_t), cmppid, NULL);
/* Call pid_array_to_buf() twice, first just to get bufsz */
ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1;
ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL);
if (!ctr->buf)
goto err2;
ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids);
kfree(pidarray);
file->private_data = ctr;
return 0;
err2:
kfree(pidarray);
err1:
kfree(ctr);
err0:
return -ENOMEM;
}
static ssize_t cpuset_tasks_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos)
{
struct ctr_struct *ctr = file->private_data;
if (*ppos + nbytes > ctr->bufsz)
nbytes = ctr->bufsz - *ppos;
if (copy_to_user(buf, ctr->buf + *ppos, nbytes))
return -EFAULT;
*ppos += nbytes;
return nbytes;
}
static int cpuset_tasks_release(struct inode *unused_inode, struct file *file)
{
struct ctr_struct *ctr;
if (file->f_mode & FMODE_READ) {
ctr = file->private_data;
kfree(ctr->buf);
kfree(ctr);
}
return 0;
}
/*
* for the common functions, 'private' gives the type of file
*/
static struct cftype cft_tasks = {
.name = "tasks",
.open = cpuset_tasks_open,
.read = cpuset_tasks_read,
.release = cpuset_tasks_release,
.private = FILE_TASKLIST,
};
static struct cftype cft_cpus = {
.name = "cpus",
.private = FILE_CPULIST,
};
static struct cftype cft_mems = {
.name = "mems",
.private = FILE_MEMLIST,
};
static struct cftype cft_cpu_exclusive = {
.name = "cpu_exclusive",
.private = FILE_CPU_EXCLUSIVE,
};
static struct cftype cft_mem_exclusive = {
.name = "mem_exclusive",
.private = FILE_MEM_EXCLUSIVE,
};
static struct cftype cft_notify_on_release = {
.name = "notify_on_release",
.private = FILE_NOTIFY_ON_RELEASE,
};
static int cpuset_populate_dir(struct dentry *cs_dentry)
{
int err;
if ((err = cpuset_add_file(cs_dentry, &cft_cpus)) < 0)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_mems)) < 0)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_cpu_exclusive)) < 0)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_mem_exclusive)) < 0)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_notify_on_release)) < 0)
return err;
if ((err = cpuset_add_file(cs_dentry, &cft_tasks)) < 0)
return err;
return 0;
}
/*
* cpuset_create - create a cpuset
* parent: cpuset that will be parent of the new cpuset.
* name: name of the new cpuset. Will be strcpy'ed.
* mode: mode to set on new inode
*
* Must be called with the semaphore on the parent inode held
*/
static long cpuset_create(struct cpuset *parent, const char *name, int mode)
{
struct cpuset *cs;
int err;
cs = kmalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return -ENOMEM;
down(&cpuset_sem);
cs->flags = 0;
if (notify_on_release(parent))
set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags);
cs->cpus_allowed = CPU_MASK_NONE;
cs->mems_allowed = NODE_MASK_NONE;
atomic_set(&cs->count, 0);
INIT_LIST_HEAD(&cs->sibling);
INIT_LIST_HEAD(&cs->children);
atomic_inc(&cpuset_mems_generation);
cs->mems_generation = atomic_read(&cpuset_mems_generation);
cs->parent = parent;
list_add(&cs->sibling, &cs->parent->children);
err = cpuset_create_dir(cs, name, mode);
if (err < 0)
goto err;
/*
* Release cpuset_sem before cpuset_populate_dir() because it
* will down() this new directory's i_sem and if we race with
* another mkdir, we might deadlock.
*/
up(&cpuset_sem);
err = cpuset_populate_dir(cs->dentry);
/* If err < 0, we have a half-filled directory - oh well ;) */
return 0;
err:
list_del(&cs->sibling);
up(&cpuset_sem);
kfree(cs);
return err;
}
static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct cpuset *c_parent = dentry->d_parent->d_fsdata;
/* the vfs holds inode->i_sem already */
return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR);
}
static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
{
struct cpuset *cs = dentry->d_fsdata;
struct dentry *d;
struct cpuset *parent;
/* the vfs holds both inode->i_sem already */
down(&cpuset_sem);
if (atomic_read(&cs->count) > 0) {
up(&cpuset_sem);
return -EBUSY;
}
if (!list_empty(&cs->children)) {
up(&cpuset_sem);
return -EBUSY;
}
spin_lock(&cs->dentry->d_lock);
parent = cs->parent;
set_bit(CS_REMOVED, &cs->flags);
list_del(&cs->sibling); /* delete my sibling from parent->children */
if (list_empty(&parent->children))
check_for_release(parent);
d = dget(cs->dentry);
cs->dentry = NULL;
spin_unlock(&d->d_lock);
cpuset_d_remove_dir(d);
dput(d);
up(&cpuset_sem);
return 0;
}
/**
* cpuset_init - initialize cpusets at system boot
*
* Description: Initialize top_cpuset and the cpuset internal file system,
**/
int __init cpuset_init(void)
{
struct dentry *root;
int err;
top_cpuset.cpus_allowed = CPU_MASK_ALL;
top_cpuset.mems_allowed = NODE_MASK_ALL;
atomic_inc(&cpuset_mems_generation);
top_cpuset.mems_generation = atomic_read(&cpuset_mems_generation);
init_task.cpuset = &top_cpuset;
err = register_filesystem(&cpuset_fs_type);
if (err < 0)
goto out;
cpuset_mount = kern_mount(&cpuset_fs_type);
if (IS_ERR(cpuset_mount)) {
printk(KERN_ERR "cpuset: could not mount!\n");
err = PTR_ERR(cpuset_mount);
cpuset_mount = NULL;
goto out;
}
root = cpuset_mount->mnt_sb->s_root;
root->d_fsdata = &top_cpuset;
root->d_inode->i_nlink++;
top_cpuset.dentry = root;
root->d_inode->i_op = &cpuset_dir_inode_operations;
err = cpuset_populate_dir(root);
out:
return err;
}
/**
* cpuset_init_smp - initialize cpus_allowed
*
* Description: Finish top cpuset after cpu, node maps are initialized
**/
void __init cpuset_init_smp(void)
{
top_cpuset.cpus_allowed = cpu_online_map;
top_cpuset.mems_allowed = node_online_map;
}
/**
* cpuset_fork - attach newly forked task to its parents cpuset.
* @p: pointer to task_struct of forking parent process.
*
* Description: By default, on fork, a task inherits its
* parents cpuset. The pointer to the shared cpuset is
* automatically copied in fork.c by dup_task_struct().
* This cpuset_fork() routine need only increment the usage
* counter in that cpuset.
**/
void cpuset_fork(struct task_struct *tsk)
{
atomic_inc(&tsk->cpuset->count);
}
/**
* cpuset_exit - detach cpuset from exiting task
* @tsk: pointer to task_struct of exiting process
*
* Description: Detach cpuset from @tsk and release it.
*
**/
void cpuset_exit(struct task_struct *tsk)
{
struct cpuset *cs;
task_lock(tsk);
cs = tsk->cpuset;
tsk->cpuset = NULL;
task_unlock(tsk);
if (atomic_dec_and_test(&cs->count)) {
down(&cpuset_sem);
check_for_release(cs);
up(&cpuset_sem);
}
}
/**
* cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
* @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
*
* Description: Returns the cpumask_t cpus_allowed of the cpuset
* attached to the specified @tsk. Guaranteed to return some non-empty
* subset of cpu_online_map, even if this means going outside the
* tasks cpuset.
**/
const cpumask_t cpuset_cpus_allowed(const struct task_struct *tsk)
{
cpumask_t mask;
down(&cpuset_sem);
task_lock((struct task_struct *)tsk);
guarantee_online_cpus(tsk->cpuset, &mask);
task_unlock((struct task_struct *)tsk);
up(&cpuset_sem);
return mask;
}
void cpuset_init_current_mems_allowed(void)
{
current->mems_allowed = NODE_MASK_ALL;
}
/*
* If the current tasks cpusets mems_allowed changed behind our backs,
* update current->mems_allowed and mems_generation to the new value.
* Do not call this routine if in_interrupt().
*/
void cpuset_update_current_mems_allowed()
{
struct cpuset *cs = current->cpuset;
if (!cs)
return; /* task is exiting */
if (current->cpuset_mems_generation != cs->mems_generation) {
down(&cpuset_sem);
guarantee_online_mems(cs, &current->mems_allowed);
current->cpuset_mems_generation = cs->mems_generation;
up(&cpuset_sem);
}
}
void cpuset_restrict_to_mems_allowed(unsigned long *nodes)
{
bitmap_and(nodes, nodes, nodes_addr(current->mems_allowed),
MAX_NUMNODES);
}
/*
* Are any of the nodes on zonelist zl allowed in current->mems_allowed?
*/
int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
{
int i;
for (i = 0; zl->zones[i]; i++) {
int nid = zl->zones[i]->zone_pgdat->node_id;
if (node_isset(nid, current->mems_allowed))
return 1;
}
return 0;
}
/*
* Is 'current' valid, and is zone z allowed in current->mems_allowed?
*/
int cpuset_zone_allowed(struct zone *z)
{
return in_interrupt() ||
node_isset(z->zone_pgdat->node_id, current->mems_allowed);
}
/*
* proc_cpuset_show()
* - Print tasks cpuset path into seq_file.
* - Used for /proc/<pid>/cpuset.
*/
static int proc_cpuset_show(struct seq_file *m, void *v)
{
struct cpuset *cs;
struct task_struct *tsk;
char *buf;
int retval = 0;
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
tsk = m->private;
down(&cpuset_sem);
task_lock(tsk);
cs = tsk->cpuset;
task_unlock(tsk);
if (!cs) {
retval = -EINVAL;
goto out;
}
retval = cpuset_path(cs, buf, PAGE_SIZE);
if (retval < 0)
goto out;
seq_puts(m, buf);
seq_putc(m, '\n');
out:
up(&cpuset_sem);
kfree(buf);
return retval;
}
static int cpuset_open(struct inode *inode, struct file *file)
{
struct task_struct *tsk = PROC_I(inode)->task;
return single_open(file, proc_cpuset_show, tsk);
}
struct file_operations proc_cpuset_operations = {
.open = cpuset_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
char *cpuset_task_status_allowed(struct task_struct *task, char *buffer)
{
buffer += sprintf(buffer, "Cpus_allowed:\t");
buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed);
buffer += sprintf(buffer, "\n");
buffer += sprintf(buffer, "Mems_allowed:\t");
buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed);
buffer += sprintf(buffer, "\n");
return buffer;
}
kernel/exit.c
View file @ 3a978e55
......@@ -25,6 +25,7 @@
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/mempolicy.h>
#include <linux/cpuset.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
......@@ -820,6 +821,7 @@ fastcall NORET_TYPE void do_exit(long code)
__exit_fs(tsk);
exit_namespace(tsk);
exit_thread();
cpuset_exit(tsk);
exit_keys(tsk);
if (group_dead && tsk->signal->leader)
......
kernel/fork.c
View file @ 3a978e55
......@@ -29,6 +29,7 @@
#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/security.h>
#include <linux/swap.h>
#include <linux/syscalls.h>
......@@ -1069,6 +1070,8 @@ static task_t *copy_process(unsigned long clone_flags,
if (unlikely(p->ptrace & PT_PTRACED))
__ptrace_link(p, current->parent);
cpuset_fork(p);
attach_pid(p, PIDTYPE_PID, p->pid);
attach_pid(p, PIDTYPE_TGID, p->tgid);
if (thread_group_leader(p)) {
......
kernel/sched.c
View file @ 3a978e55
......@@ -40,6 +40,7 @@
#include <linux/timer.h>
#include <linux/rcupdate.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/percpu.h>
#include <linux/kthread.h>
#include <linux/seq_file.h>
......@@ -3539,6 +3540,7 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
{
task_t *p;
int retval;
cpumask_t cpus_allowed;
lock_cpu_hotplug();
read_lock(&tasklist_lock);
......@@ -3563,6 +3565,8 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
!capable(CAP_SYS_NICE))
goto out_unlock;
cpus_allowed = cpuset_cpus_allowed(p);
cpus_and(new_mask, new_mask, cpus_allowed);
retval = set_cpus_allowed(p, new_mask);
out_unlock:
......@@ -4240,7 +4244,7 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *tsk)
/* No more Mr. Nice Guy. */
if (dest_cpu == NR_CPUS) {
cpus_setall(tsk->cpus_allowed);
tsk->cpus_allowed = cpuset_cpus_allowed(tsk);
dest_cpu = any_online_cpu(tsk->cpus_allowed);
/*
......
mm/mempolicy.c
View file @ 3a978e55
......@@ -67,6 +67,7 @@
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/nodemask.h>
#include <linux/cpuset.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/string.h>
......@@ -167,6 +168,10 @@ static int get_nodes(unsigned long *nodes, unsigned long __user *nmask,
if (copy_from_user(nodes, nmask, nlongs*sizeof(unsigned long)))
return -EFAULT;
nodes[nlongs-1] &= endmask;
/* Update current mems_allowed */
cpuset_update_current_mems_allowed();
/* Ignore nodes not set in current->mems_allowed */
cpuset_restrict_to_mems_allowed(nodes);
return mpol_check_policy(mode, nodes);
}
......@@ -655,8 +660,10 @@ static struct zonelist *zonelist_policy(unsigned gfp, struct mempolicy *policy)
break;
case MPOL_BIND:
/* Lower zones don't get a policy applied */
/* Careful: current->mems_allowed might have moved */
if (gfp >= policy_zone)
return policy->v.zonelist;
if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
return policy->v.zonelist;
/*FALL THROUGH*/
case MPOL_INTERLEAVE: /* should not happen */
case MPOL_DEFAULT:
......@@ -747,6 +754,8 @@ alloc_page_vma(unsigned gfp, struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = get_vma_policy(vma, addr);
cpuset_update_current_mems_allowed();
if (unlikely(pol->policy == MPOL_INTERLEAVE)) {
unsigned nid;
if (vma) {
......@@ -784,6 +793,8 @@ struct page *alloc_pages_current(unsigned gfp, unsigned order)
{
struct mempolicy *pol = current->mempolicy;
if (!in_interrupt())
cpuset_update_current_mems_allowed();
if (!pol || in_interrupt())
pol = &default_policy;
if (pol->policy == MPOL_INTERLEAVE)
......
mm/page_alloc.c
View file @ 3a978e55
......@@ -31,6 +31,7 @@
#include <linux/topology.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
......@@ -765,6 +766,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order,
classzone_idx, 0, 0))
continue;
if (!cpuset_zone_allowed(z))
continue;
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
......@@ -783,6 +787,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order,
gfp_mask & __GFP_HIGH))
continue;
if (!cpuset_zone_allowed(z))
continue;
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
......@@ -792,6 +799,8 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order,
if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) && !in_interrupt()) {
/* go through the zonelist yet again, ignoring mins */
for (i = 0; (z = zones[i]) != NULL; i++) {
if (!cpuset_zone_allowed(z))
continue;
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
......@@ -831,6 +840,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order,
gfp_mask & __GFP_HIGH))
continue;
if (!cpuset_zone_allowed(z))
continue;
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
......@@ -847,6 +859,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order,
classzone_idx, 0, 0))
continue;
if (!cpuset_zone_allowed(z))
continue;
page = buffered_rmqueue(z, order, gfp_mask);
if (page)
goto got_pg;
......@@ -1490,6 +1505,7 @@ void __init build_all_zonelists(void)
for_each_online_node(i)
build_zonelists(NODE_DATA(i));
printk("Built %i zonelists\n", num_online_nodes());
cpuset_init_current_mems_allowed();
}
/*
......
mm/vmscan.c
View file @ 3a978e55
......@@ -30,6 +30,7 @@
#include <linux/rmap.h>
#include <linux/topology.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/notifier.h>
#include <linux/rwsem.h>
......@@ -865,6 +866,9 @@ shrink_caches(struct zone **zones, struct scan_control *sc)
if (zone->present_pages == 0)
continue;
if (!cpuset_zone_allowed(zone))
continue;
zone->temp_priority = sc->priority;
if (zone->prev_priority > sc->priority)
zone->prev_priority = sc->priority;
......@@ -908,6 +912,9 @@ int try_to_free_pages(struct zone **zones,
for (i = 0; zones[i] != NULL; i++) {
struct zone *zone = zones[i];
if (!cpuset_zone_allowed(zone))
continue;
zone->temp_priority = DEF_PRIORITY;
lru_pages += zone->nr_active + zone->nr_inactive;
}
......@@ -948,8 +955,14 @@ int try_to_free_pages(struct zone **zones,
blk_congestion_wait(WRITE, HZ/10);
}
out:
for (i = 0; zones[i] != 0; i++)
zones[i]->prev_priority = zones[i]->temp_priority;
for (i = 0; zones[i] != 0; i++) {
struct zone *zone = zones[i];
if (!cpuset_zone_allowed(zone))
continue;
zone->prev_priority = zone->temp_priority;
}
return ret;
}
......@@ -1210,6 +1223,8 @@ void wakeup_kswapd(struct zone *zone, int order)
return;
if (pgdat->kswapd_max_order < order)
pgdat->kswapd_max_order = order;
if (!cpuset_zone_allowed(zone))
return;
if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
return;
wake_up_interruptible(&zone->zone_pgdat->kswapd_wait);
......
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