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2020-12-03completion: Drop init_completion defineMauro Carvalho Chehab1-3/+2
Changeset cd8084f91c02 ("locking/lockdep: Apply crossrelease to completions") added a CONFIG_LOCKDEP_COMPLETE (that was later renamed to CONFIG_LOCKDEP_COMPLETIONS). Such changeset renamed the init_completion, and add a macro that would either run a modified version or the original code. However, such code reported too many false positives. So, it ended being dropped later on by changeset e966eaeeb623 ("locking/lockdep: Remove the cross-release locking checks"). Yet, the define remained there as just: #define init_completion(x) __init_completion(x) Get rid of the define, and return __init_completion() function to its original name. Fixes: e966eaeeb623 ("locking/lockdep: Remove the cross-release locking checks") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/e657bfc533545c185b1c3c55926a449ead56a88b.1606823973.git.mchehab+huawei@kernel.org
2020-03-21completion: Use simple wait queuesThomas Gleixner1-4/+4
completion uses a wait_queue_head_t to enqueue waiters. wait_queue_head_t contains a spinlock_t to protect the list of waiters which excludes it from being used in truly atomic context on a PREEMPT_RT enabled kernel. The spinlock in the wait queue head cannot be replaced by a raw_spinlock because: - wait queues can have custom wakeup callbacks, which acquire other spinlock_t locks and have potentially long execution times - wake_up() walks an unbounded number of list entries during the wake up and may wake an unbounded number of waiters. For simplicity and performance reasons complete() should be usable on PREEMPT_RT enabled kernels. completions do not use custom wakeup callbacks and are usually single waiter, except for a few corner cases. Replace the wait queue in the completion with a simple wait queue (swait), which uses a raw_spinlock_t for protecting the waiter list and therefore is safe to use inside truly atomic regions on PREEMPT_RT. There is no semantical or functional change: - completions use the exclusive wait mode which is what swait provides - complete() wakes one exclusive waiter - complete_all() wakes all waiters while holding the lock which protects the wait queue against newly incoming waiters. The conversion to swait preserves this behaviour. complete_all() might cause unbound latencies with a large number of waiters being woken at once, but most complete_all() usage sites are either in testing or initialization code or have only a really small number of concurrent waiters which for now does not cause a latency problem. Keep it simple for now. The fixup of the warning check in the USB gadget driver is just a straight forward conversion of the lockless waiter check from one waitqueue type to the other. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20200321113242.317954042@linutronix.de
2018-01-08locking/lockdep: Remove cross-release leftoversIngo Molnar1-1/+0
There's two cross-release leftover facilities: - the crossrelease_hist_*() irq-tracing callbacks (NOPs currently) - the complete_release_commit() callback (NOP as well) Remove them. Cc: David Sterba <dsterba@suse.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-12locking/lockdep: Remove the cross-release locking checksIngo Molnar1-45/+0
This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y), while it found a number of old bugs initially, was also causing too many false positives that caused people to disable lockdep - which is arguably a worse overall outcome. If we disable cross-release by default but keep the code upstream then in practice the most likely outcome is that we'll allow the situation to degrade gradually, by allowing entropy to introduce more and more false positives, until it overwhelms maintenance capacity. Another bad side effect was that people were trying to work around the false positives by uglifying/complicating unrelated code. There's a marked difference between annotating locking operations and uglifying good code just due to bad lock debugging code ... This gradual decrease in quality happened to a number of debugging facilities in the kernel, and lockdep is pretty complex already, so we cannot risk this outcome. Either cross-release checking can be done right with no false positives, or it should not be included in the upstream kernel. ( Note that it might make sense to maintain it out of tree and go through the false positives every now and then and see whether new bugs were introduced. ) Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar1-0/+1
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-25sched/completions: Add support for initializing completions with lockdep_mapByungchul Park1-0/+14
Sometimes we want to initialize completions with sparate lockdep maps to assign lock classes as desired. For example, the workqueue code needs to directly manage lockdep maps, since only the code is aware of how to classify lockdep maps properly. Provide additional macros initializing completions in that way. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-8-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25locking/lockdep, sched/completions: Change the prefix of lock name for ↵Byungchul Park1-2/+2
completion variables CONFIG_LOCKDEP_COMPLETIONS uses "(complete)" as a prefix of lock name for completion variable. However, what we should use here is a noun - so use "(completion)" instead. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-4-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29sched/completion: Avoid unnecessary stack allocation for ↵Boqun Feng1-1/+1
COMPLETION_INITIALIZER_ONSTACK() In theory, COMPLETION_INITIALIZER_ONSTACK() should never affect the stack allocation of the caller. However, on some compilers, a temporary structure was allocated for the return value of COMPLETION_INITIALIZER_ONSTACK(). For example in write_journal() with LOCKDEP_COMPLETIONS=y (GCC is 7.1.1): io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp); 2462: e8 00 00 00 00 callq 2467 <write_journal+0x47> 2467: 48 8d 85 80 fd ff ff lea -0x280(%rbp),%rax 246e: 48 c7 c6 00 00 00 00 mov $0x0,%rsi 2475: 48 c7 c2 00 00 00 00 mov $0x0,%rdx x->done = 0; 247c: c7 85 90 fd ff ff 00 movl $0x0,-0x270(%rbp) 2483: 00 00 00 init_waitqueue_head(&x->wait); 2486: 48 8d 78 18 lea 0x18(%rax),%rdi 248a: e8 00 00 00 00 callq 248f <write_journal+0x6f> if (commit_start + commit_sections <= ic->journal_sections) { 248f: 41 8b 87 a8 00 00 00 mov 0xa8(%r15),%eax io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp); 2496: 48 8d bd e8 f9 ff ff lea -0x618(%rbp),%rdi 249d: 48 8d b5 90 fd ff ff lea -0x270(%rbp),%rsi 24a4: b9 17 00 00 00 mov $0x17,%ecx 24a9: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) if (commit_start + commit_sections <= ic->journal_sections) { 24ac: 41 39 c6 cmp %eax,%r14d io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp); 24af: 48 8d bd 90 fd ff ff lea -0x270(%rbp),%rdi 24b6: 48 8d b5 e8 f9 ff ff lea -0x618(%rbp),%rsi 24bd: b9 17 00 00 00 mov $0x17,%ecx 24c2: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) We can obviously see the temporary structure allocated, and the compiler also does two meaningless memcpy with "rep movsq". And according to: https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement-Exprs The return value of a statement expression is returned by value, so the temporary variable is created in COMPLETION_INITIALIZER_ONSTACK(), and that's why the temporary structures are allocted. To fix this, make the brace block in COMPLETION_INITIALIZER_ONSTACK() return a pointer and dereference it outside the block rather than return the whole structure, in this way, we are able to teach the compiler not to do the unnecessary stack allocation. This could also reduce the stack size even if !LOCKDEP, for example in write_journal(), compiled with gcc 7.1.1, the result of command: objdump -d drivers/md/dm-integrity.o | ./scripts/checkstack.pl x86 before: 0x0000246a write_journal [dm-integrity.o]: 696 after: 0x00002b7a write_journal [dm-integrity.o]: 296 Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/20170823152542.5150-3-boqun.feng@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-17locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONSByungchul Park1-4/+4
'complete' is an adjective and LOCKDEP_COMPLETE sounds like 'lockdep is complete', so pick a better name that uses a noun. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/1502960261-16206-3-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10locking/lockdep: Apply crossrelease to completionsByungchul Park1-1/+44
Although wait_for_completion() and its family can cause deadlock, the lock correctness validator could not be applied to them until now, because things like complete() are usually called in a different context from the waiting context, which violates lockdep's assumption. Thanks to CONFIG_LOCKDEP_CROSSRELEASE, we can now apply the lockdep detector to those completion operations. Applied it. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-10-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-15sched: remove INIT_COMPLETIONWolfram Sang1-10/+0
All users are converted over to reinit_completion(). Remove the old macro now. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15sched: replace INIT_COMPLETION with reinit_completionWolfram Sang1-3/+15
For the casual device driver writer, it is hard to remember when to use init_completion (to init a completion structure) or INIT_COMPLETION (to *reinit* a completion structure). Furthermore, while all other completion functions exepct a pointer as a parameter, INIT_COMPLETION does not. To make it easier to remember which function to use and to make code more readable, introduce a new inline function with the proper name and consistent argument type. Update the kernel-doc for init_completion while we are here. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-06sched: Move completion code from core.c to completion.cPeter Zijlstra1-1/+1
Completions already have their own header file: linux/completion.h Move the implementation out of kernel/sched/core.c and into its own file: kernel/sched/completion.c. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-x2y49rmxu5dljt66ai2lcfuw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Rename sched.c as sched/core.c in comments and DocumentationViresh Kumar1-1/+1
Most of the stuff from kernel/sched.c was moved to kernel/sched/core.c long time back and the comments/Documentation never got updated. I figured it out when I was going through sched-domains.txt and so thought of fixing it globally. I haven't crossed check if the stuff that is referenced in sched/core.c by all these files is still present and hasn't changed as that wasn't the motive behind this patch. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/cdff76a265326ab8d71922a1db5be599f20aad45.1370329560.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-15sched: add wait_for_completion_io[_timeout]Vladimir Davydov1-0/+3
The only difference between wait_for_completion[_timeout]() and wait_for_completion_io[_timeout]() is that the latter calls io_schedule_timeout() instead of schedule_timeout() so that the caller is accounted as waiting for IO, not just sleeping. These functions can be used for correct iowait time accounting when the completion struct is actually used for waiting for IO (e.g. completion of a bio request in the block layer). Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-01-05sched: Change wait_for_completion_*_timeout() to return a signed longNeilBrown1-4/+4
wait_for_completion_*_timeout() can return: 0: if the wait timed out -ve: if the wait was interrupted +ve: if the completion was completed. As they currently return an 'unsigned long', the last two cases are not easily distinguished which can easily result in buggy code, as is the case for the recently added wait_for_completion_interruptible_timeout() call in net/sunrpc/cache.c So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT is LONG_MAX, a large +ve return value should never overflow. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110105125016.64ccab0e@notabene.brown> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-27docbook: add more wait/wake/completion to device-drivers docbookRandy Dunlap1-5/+5
Add more wait, wake, and completion interfaces to the device-drivers docbook. Fix kernel-doc notation in the added files. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-29sched: add wait_for_completion_killable_timeoutSage Weil1-0/+2
Add missing _killable_timeout variant for wait_for_completion that will return when a timeout expires or the task is killed. CC: Ingo Molnar <mingo@elte.hu> CC: Andreas Herrmann <andreas.herrmann3@amd.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Sage Weil <sage@newdream.net>
2008-08-26sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txtKevin Diggs1-0/+41
This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15completions: uninline try_wait_for_completion and completion_doneDave Chinner1-44/+2
m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-13[XFS] extend completions to provide XFS object flush requirementsDavid Chinner1-0/+45
XFS object flushing doesn't quite match existing completion semantics. It mixed exclusive access with completion. That is, we need to mark an object as being flushed before flushing it to disk, and then block any other attempt to flush it until the completion occurs. We do this but adding an extra count to the completion before we start using them. However, we still need to determine if there is a completion in progress, and allow no-blocking attempts fo completions to decrement the count. To do this we introduce: int try_wait_for_completion(struct completion *x) returns a failure status if done == 0, otherwise decrements done to zero and returns a "started" status. This is provided to allow counted completions to begin safely while holding object locks in inverted order. int completion_done(struct completion *x) returns 1 if there is no waiter, 0 if there is a waiter (i.e. a completion in progress). This replaces the use of semaphores for providing this exclusion and completion mechanism. SGI-PV: 981498 SGI-Modid: xfs-linux-melb:xfs-kern:31816a Signed-off-by: David Chinner <david@fromorbit.com> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2007-12-07Add wait_for_completion_killableMatthew Wilcox1-0/+1
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-10-24sched: fix fastcall mismatch in completion APIsIngo Molnar1-9/+9
Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-07-11[PATCH] lockdep: clean up completion initializer in smpboot.cIngo Molnar1-1/+4
Clean up lockdep on-stack-completion initializer. (This also removes the dependency on waitqueue_lock_key.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-04[PATCH] lockdep: add DECLARE_COMPLETION_ONSTACK() APIIngo Molnar1-0/+12
lockdep needs to have the waitqueue lock initialized for on-stack waitqueues implicitly initialized by DECLARE_COMPLETION(). Introduce the API. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-17Linux-2.6.12-rc2Linus Torvalds1-0/+42
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!