- 19 Jul, 2007 40 commits
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Peter Zijlstra authored
__acquire | lock _____ | \ | __contended | | | wait | _______/ |/ | __acquired | __release | unlock We measure acquisition and contention bouncing. This is done by recording a cpu stamp in each lock instance. Contention bouncing requires the cpu stamp to be set on acquisition. Hence we move __acquired into the generic path. __acquired is then used to measure acquisition bouncing by comparing the current cpu with the old stamp before replacing it. __contended is used to measure contention bouncing (only useful for preemptable locks) [akpm@linux-foundation.org: cleanups] Signed-off-by:Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Peter Zijlstra authored
the two init sites resulted in inconsistend names for the lock class. Signed-off-by:
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Peter Zijlstra authored
- update the copyright notices - use the default hash function - fix a thinko in a BUILD_BUG_ON - add a WARN_ON to spot inconsitent naming - fix a termination issue in /proc/lock_stat [akpm@linux-foundation.org: cleanups] Signed-off-by:
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Peter Zijlstra authored
Call the new lockstat tracking functions from the various lock primitives. Signed-off-by:
Jason Baron <jbaron@redhat.com> Signed-off-by:
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Peter Zijlstra authored
Present all this fancy new lock statistics information: *warning, _wide_ output ahead* (output edited for purpose of brevity) # cat /proc/lock_stat lock_stat version 0.1 ----------------------------------------------------------------------------------------------------------------------------------------------------------------- class name contentions waittime-min waittime-max waittime-total acquisitions holdtime-min holdtime-max holdtime-total ----------------------------------------------------------------------------------------------------------------------------------------------------------------- &inode->i_mutex: 14458 6.57 398832.75 2469412.23 6768876 0.34 11398383.65 339410830.89 --------------- &inode->i_mutex 4486 [<ffffffff802a08f9>] pipe_wait+0x86/0x8d &inode->i_mutex 0 [<ffffffff802a01e8>] pipe_write_fasync+0x29/0x5d &inode->i_mutex 0 [<ffffffff802a0e18>] pipe_read+0x74/0x3a5 &inode->i_mutex 0 [<ffffffff802a1a6a>] do_lookup+0x81/0x1ae ................................................................................................................................................................. &inode->i_data.tree_lock-W: 491 0.27 62.47 493.89 2477833 0.39 468.89 1146584.25 &inode->i_data.tree_lock-R: 65 0.44 4.27 48.78 26288792 0.36 184.62 10197458.24 -------------------------- &inode->i_data.tree_lock 46 [<ffffffff80277095>] __do_page_cache_readahead+0x69/0x24f &inode->i_data.tree_lock 31 [<ffffffff8026f9fb>] add_to_page_cache+0x31/0xba &inode->i_data.tree_lock 0 [<ffffffff802770ee>] __do_page_cache_readahead+0xc2/0x24f &inode->i_data.tree_lock 0 [<ffffffff8026f6e4>] find_get_page+0x1a/0x58 ................................................................................................................................................................. proc_inum_idr.lock: 0 0.00 0.00 0.00 36 0.00 65.60 148.26 proc_subdir_lock: 0 0.00 0.00 0.00 3049859 0.00 106.81 1563212.42 shrinker_rwsem-W: 0 0.00 0.00 0.00 5 0.00 1.73 3.68 shrinker_rwsem-R: 0 0.00 0.00 0.00 633 2.57 246.57 10909.76 'contentions' and 'acquisitions' are the number of such events measured (since the last reset). The waittime- and holdtime- (min, max, total) numbers are presented in microseconds. If there are any contention points, the lock class is presented in the block format (as i_mutex and tree_lock above), otherwise a single line of output is presented. The output is sorted on absolute number of contentions (read + write), this should get the worst offenders presented first, so that: # grep : /proc/lock_stat | head will quickly show who's bad. The stats can be reset using: # echo 0 > /proc/lock_stat [bunk@stusta.de: make 2 functions static] [akpm@linux-foundation.org: fix printk warning] Signed-off-by:Adrian Bunk <bunk@stusta.de> Signed-off-by:
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Peter Zijlstra authored
Introduce the core lock statistics code. Lock statistics provides lock wait-time and hold-time (as well as the count of corresponding contention and acquisitions events). Also, the first few call-sites that encounter contention are tracked. Lock wait-time is the time spent waiting on the lock. This provides insight into the locking scheme, that is, a heavily contended lock is indicative of a too coarse locking scheme. Lock hold-time is the duration the lock was held, this provides a reference for the wait-time numbers, so they can be put into perspective. 1) lock 2) ... do stuff .. unlock 3) The time between 1 and 2 is the wait-time. The time between 2 and 3 is the hold-time. The lockdep held-lock tracking code is reused, because it already collects locks into meaningful groups (classes), and because it is an existing infrastructure for lock instrumentation. Currently lockdep tracks lock acquisition with two hooks: lock() lock_acquire() _lock() ... code protected by lock ... unlock() lock_release() _unlock() We need to extend this with two more hooks, in order to measure contention. lock_contended() - used to measure contention events lock_acquired() - completion of the contention These are then placed the following way: lock() lock_acquire() if (!_try_lock()) lock_contended() _lock() lock_acquired() ... do locked stuff ... unlock() lock_release() _unlock() (Note: the try_lock() 'trick' is used to avoid instrumenting all platform dependent lock primitive implementations.) It is also possible to toggle the two lockdep features at runtime using: /proc/sys/kernel/prove_locking /proc/sys/kernel/lock_stat (esp. turning off the O(n^2) prove_locking functionaliy can help) [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: nuke unneeded ifdefs] Signed-off-by: -
Peter Zijlstra authored
Move code around to get fewer but larger #ifdef sections. Break some in-function #ifdefs out into their own functions. Signed-off-by:
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Peter Zijlstra authored
Ensure that all of the lock dependency tracking code is under CONFIG_PROVE_LOCKING. This allows us to use the held lock tracking code for other purposes. Signed-off-by:
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Peter Zijlstra authored
Use the lockdep infrastructure to track lock contention and other lock statistics. It tracks lock contention events, and the first four unique call-sites that encountered contention. It also measures lock wait-time and hold-time in nanoseconds. The minimum and maximum times are tracked, as well as a total (which together with the number of event can give the avg). All statistics are done per lock class, per write (exclusive state) and per read (shared state). The statistics are collected per-cpu, so that the collection overhead is minimized via having no global cachemisses. This new lock statistics feature is independent of the lock dependency checking traditionally done by lockdep; it just shares the lock tracking code. It is also possible to enable both and runtime disabled either component - thereby avoiding the O(n^2) lock chain walks for instance. This patch: raw_spinlock_t should not use lockdep (and doesn't) since lockdep itself relies on it. Signed-off-by:
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Jan Harkes authored
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Jan Harkes <jaharkes@cs.cmu.edu> Signed-off-by:
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Jan Harkes authored
Similar information can easily be obtained with strace -c. Signed-off-by:
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Jan Harkes authored
The sb_info structure only contains a single pointer to the character device, there is no need for the added indirection. Signed-off-by:
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Jan Harkes authored
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Jan Harkes authored
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Jan Harkes authored
Venus returns an ENOENT error on open, so we shouldn't try to grab the filehandle for the returned fd. Signed-off-by:
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Jan Harkes authored
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Jan Harkes authored
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Jan Harkes authored
We ignore signals for about 30 seconds to give userspace a chance to see the upcall. As we did not block signals we ended up in a busy loop for the remainder of the period when a signal is received. Signed-off-by:
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Jan Harkes authored
Make the code that processes upcall responses more straightforward, uncovered at least one bad assumption. We trusted that vc_inuse would be 0 when upcalls are aborted, however the device may have been reopened. Signed-off-by:
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Jan Harkes authored
- Make sure device index is not a negative number. - Unlink queued requests when the device is closed to avoid passing them to the next opener. Signed-off-by:
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Jan Harkes authored
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Jan Harkes authored
Set MS_NOATIME flag to avoid unnecessary calls when the coda inode is accessed. Also, set statfs.f_bsize to 4k. 1k is obviously too small for the suggested IO size. Signed-off-by:
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Jan Harkes authored
A directory without children may still be busy when it is the cwd for some process. We can safely remove such a directory because the VFS prevents further operations. Also we don't need to call d_delete as it is already called in vfs_rmdir. Signed-off-by:
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Jan Harkes authored
The Coda client sets the directory link count to 1 when it isn't sure how many subdirectories we have. In this case we shouldn't change the link count in the kernel when a subdirectory is created or removed. Signed-off-by:
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Jan Harkes authored
Change the epoch value to forces a refresh instead of clearing the cached rights mask and block all further accesses to the object. Signed-off-by:
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Jan Harkes authored
When open fails the fd in the response is uninitialized and we ended up taking a reference on the file struct and never released it. Signed-off-by:
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Roland McGrath authored
This change passes the --build-id when linking the kernel and when linking modules, if ld supports it. This is a new GNU ld option that synthesizes an ELF note section inside the read-only data. The note in this section contains unique identifying bits called the "build ID", which are generated so as to be different for any two linked ELF files that aren't identical. The build ID can be recovered from stripped files, memory dumps, etc. and used to look up the original program built, locate debuginfo or other details or history associated with it. For normal program linking, the compiler passes --build-id to ld by default, but the option is needed when using ld directly as we do. Signed-off-by:
Roland McGrath <roland@redhat.com> Cc: Andi Kleen <ak@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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Roland McGrath authored
This patch adds the /sys/kernel/notes magic file. Reading this delivers the contents of the kernel's .notes section. This lets userland easily glean any detailed information about the running kernel's build that was stored there at compile time. Signed-off-by:
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Roland McGrath authored
This changes the s390 linker script to use the asm-generic NOTES macro so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by:
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Roland McGrath authored
This changes the powerpc linker script to use the asm-generic NOTES macro so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by:
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Roland McGrath authored
This changes the alpha linker script to use the asm-generic NOTES macro so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by:
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Roland McGrath authored
This changes the x86_64 linker script to use the asm-generic NOTES macro so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by:
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Roland McGrath authored
This changes the i386 linker script and the asm-generic macro it uses so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by:
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Mingming Cao authored
Looking at the current linus-git tree jbd_debug() define in include/linux/jbd2.h extern u8 journal_enable_debug; #define jbd_debug(n, f, a...) \ do { \ if ((n) <= journal_enable_debug) { \ printk (KERN_DEBUG "(%s, %d): %s: ", \ __FILE__, __LINE__, __FUNCTION__); \ printk (f, ## a); \ } \ } while (0) > fs/ext4/inode.c: In function âext4_write_inodeâ: > fs/ext4/inode.c:2906: warning: comparison is always true due to limited > range of data type > > fs/jbd2/recovery.c: In function âjbd2_journal_recoverâ: > fs/jbd2/recovery.c:254: warning: comparison is always true due to > limited range of data type > fs/jbd2/recovery.c:257: warning: comparison is always true due to > limited range of data type > > fs/jbd2/recovery.c: In function âjbd2_journal_skip_recoveryâ: > fs/jbd2/recovery.c:301: warning: comparison is always true due to > limited range of data type > Noticed all warnings are occurs when the debug level is 0. Then found the "jbd2: Move jbd2-debug file to debugfs" patch http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0f49d5d019afa4e94253bfc92f0daca3badb990b changed the jbd2_journal_enable_debug from int type to u8, makes the jbd_debug comparision is always true when the debugging level is 0. Thus the compile warning occurs. Thought about changing the jbd2_journal_enable_debug data type back to int, but can't, because the jbd2-debug is moved to debug fs, where calling debugfs_create_u8() to create the debugfs entry needs the value to be u8 type. Even if we changed the data type back to int, the code is still buggy, kernel should not print jbd2 debug message if the jbd2_journal_enable_debug is set to 0. But this is not the case. The fix is change the level of debugging to 1. The same should fixed in ext3/JBD, but currently ext3 jbd-debug via /proc fs is broken, so we probably should fix it all together. Signed-off-by:Mingming Cao <cmm@us.ibm.com> Cc: Jeff Garzik <jeff@garzik.org> Cc: Theodore Tso <tytso@mit.edu> Signed-off-by:
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Andy Whitcroft authored
This version brings a number of new checks, and a number of bug fixes. Of note: - warnings for multiple assignments per line - warnings for multiple declarations per line - checks for single statement blocks with braces This patch includes an update for feature-removal-schedule.txt to better target checks. Andy Whitcroft (12): Version: 0.08 only apply printk checks where there is a string literal allow suppression of errors for when no patch is found warn about multiple assignments warn on declaration of multiple variables check for kfree() with needless null check check for single statement braced blocks check for aggregate initialisation on the next line handle the => operator check for spaces between function name and open parenthesis move to explicit Check: entries in feature-removal-schedule.txt handle pointer attributes Signed-off-by:Andy Whitcroft <apw@shadowen.org> Signed-off-by:
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Rolf Eike Beer authored
Signed-off-by:
Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by:
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Ingo Molnar authored
Update the MAINTAINERS file: Thomas Gleixner has been the de-facto maintainer of POSIX timers and clocks for quite some time. Signed-off-by:
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Adrian Bunk authored
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Kawai, Hidehiro authored
This patch adds the documentation for /proc/<pid>/coredump_filter. Signed-off-by:
Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by:
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Kawai, Hidehiro authored
This patch enables core dump filtering for ELF-FDPIC-formatted core file. Signed-off-by:
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