user/sven/linux.git/Documentation/locking, branch v4.20.7

Merge tag 'docs-4.20' of git://git.lwn.net/linux

2018-10-24T17:01:11Z

Pull documentation updates from Jonathan Corbet: "This is a fairly typical cycle for documentation. There's some welcome readability improvements for the formatted output, some LICENSES updates including the addition of the ISC license, the removal of the unloved and unmaintained 00-INDEX files, the deprecated APIs document from Kees, more MM docs from Mike Rapoport, and the usual pile of typo fixes and corrections" * tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits) docs: Fix typos in histogram.rst docs: Introduce deprecated APIs list kernel-doc: fix declaration type determination doc: fix a typo in adding-syscalls.rst docs/admin-guide: memory-hotplug: remove table of contents doc: printk-formats: Remove bogus kobject references for device nodes Documentation: preempt-locking: Use better example dm flakey: Document "error_writes" feature docs/completion.txt: Fix a couple of punctuation nits LICENSES: Add ISC license text LICENSES: Add note to CDDL-1.0 license that it should not be used docs/core-api: memory-hotplug: add some details about locking internals docs/core-api: rename memory-hotplug-notifier to memory-hotplug docs: improve readability for people with poorer eyesight yama: clarify ptrace_scope=2 in Yama documentation docs/vm: split memory hotplug notifier description to Documentation/core-api docs: move memory hotplug description into admin-guide/mm doc: Fix acronym "FEKEK" in ecryptfs docs: fix some broken documentation references iommu: Fix passthrough option documentation ...

Documentation/lockstat: Fix trivial typo

2018-10-02T08:59:25Z

Fix incorrect line number in example output Signed-off-by: Andrew Murray Cc: Jiri Kosina Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1538391663-54524-1-git-send-email-andrew.murray@arm.com Signed-off-by: Ingo Molnar

Drop all 00-INDEX files from Documentation/

2018-09-09T21:08:58Z

This is a respin with a wider audience (all that get_maintainer returned) and I know this spams a *lot* of people. Not sure what would be the correct way, so my apologies for ruining your inbox. The 00-INDEX files are supposed to give a summary of all files present in a directory, but these files are horribly out of date and their usefulness is brought into question. Often a simple "ls" would reveal the same information as the filenames are generally quite descriptive as a short introduction to what the file covers (it should not surprise anyone what Documentation/sched/sched-design-CFS.txt covers) A few years back it was mentioned that these files were no longer really needed, and they have since then grown further out of date, so perhaps it is time to just throw them out. A short status yields the following _outdated_ 00-INDEX files, first counter is files listed in 00-INDEX but missing in the directory, last is files present but not listed in 00-INDEX. List of outdated 00-INDEX: Documentation: (4/10) Documentation/sysctl: (0/1) Documentation/timers: (1/0) Documentation/blockdev: (3/1) Documentation/w1/slaves: (0/1) Documentation/locking: (0/1) Documentation/devicetree: (0/5) Documentation/power: (1/1) Documentation/powerpc: (0/5) Documentation/arm: (1/0) Documentation/x86: (0/9) Documentation/x86/x86_64: (1/1) Documentation/scsi: (4/4) Documentation/filesystems: (2/9) Documentation/filesystems/nfs: (0/2) Documentation/cgroup-v1: (0/2) Documentation/kbuild: (0/4) Documentation/spi: (1/0) Documentation/virtual/kvm: (1/0) Documentation/scheduler: (0/2) Documentation/fb: (0/1) Documentation/block: (0/1) Documentation/networking: (6/37) Documentation/vm: (1/3) Then there are 364 subdirectories in Documentation/ with several files that are missing 00-INDEX alltogether (and another 120 with a single file and no 00-INDEX). I don't really have an opinion to whether or not we /should/ have 00-INDEX, but the above 00-INDEX should either be removed or be kept up to date. If we should keep the files, I can try to keep them updated, but I rather not if we just want to delete them anyway. As a starting point, remove all index-files and references to 00-INDEX and see where the discussion is going. Signed-off-by: Henrik Austad Acked-by: "Paul E. McKenney" Just-do-it-by: Steven Rostedt Reviewed-by: Jens Axboe Acked-by: Paul Moore Acked-by: Greg Kroah-Hartman Acked-by: Mark Brown Acked-by: Mike Rapoport Cc: [Almost everybody else] Signed-off-by: Jonathan Corbet

locking: Implement an algorithm choice for Wound-Wait mutexes

2018-07-03T07:44:36Z

The current Wound-Wait mutex algorithm is actually not Wound-Wait but Wait-Die. Implement also Wound-Wait as a per-ww-class choice. Wound-Wait is, contrary to Wait-Die a preemptive algorithm and is known to generate fewer backoffs. Testing reveals that this is true if the number of simultaneous contending transactions is small. As the number of simultaneous contending threads increases, Wait-Wound becomes inferior to Wait-Die in terms of elapsed time. Possibly due to the larger number of held locks of sleeping transactions. Update documentation and callers. Timings using git://people.freedesktop.org/~thomash/ww_mutex_test tag patch-18-06-15 Each thread runs 100000 batches of lock / unlock 800 ww mutexes randomly chosen out of 100000. Four core Intel x86_64: Algorithm #threads Rollbacks time Wound-Wait 4 ~100 ~17s. Wait-Die 4 ~150000 ~19s. Wound-Wait 16 ~360000 ~109s. Wait-Die 16 ~450000 ~82s. Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Gustavo Padovan Cc: Maarten Lankhorst Cc: Sean Paul Cc: David Airlie Cc: Davidlohr Bueso Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Greg Kroah-Hartman Cc: linux-doc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Co-authored-by: Peter Zijlstra Signed-off-by: Thomas Hellstrom Acked-by: Peter Zijlstra (Intel) Acked-by: Ingo Molnar

locking: WW mutex cleanup

2018-07-03T07:42:40Z

Make the WW mutex code more readable by adding comments, splitting up functions and pointing out that we're actually using the Wait-Die algorithm. Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Gustavo Padovan Cc: Maarten Lankhorst Cc: Sean Paul Cc: David Airlie Cc: Davidlohr Bueso Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Greg Kroah-Hartman Cc: linux-doc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Co-authored-by: Thomas Hellstrom Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Hellstrom Acked-by: Ingo Molnar

Merge tag 'v4.16-rc2' into locking/core, to refresh the branch

2018-02-21T08:57:55Z

Signed-off-by: Ingo Molnar

Documentation/locking/lockdep: Add section about available annotations

2018-02-14T11:01:22Z

Add section about annotations that can be used to perform additional runtime checking of locking correctness: assert that certain locks are held and prevent accidental unlocking. Signed-off-by: Juri Lelli Acked-by: Peter Zijlstra (Intel) Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20180213185519.18186-3-juri.lelli@redhat.com Signed-off-by: Ingo Molnar

Documentation/locking/lockdep: Update info about states

2018-02-14T11:01:22Z

Commit: d92a8cfcb37e ("locking/lockdep: Rework FS_RECLAIM annotation") removed the 'reclaim_fs' lockdep STATE. Reflect the change in the documentation. While we are at it, also clarify the formula to calculate the number of state bits. Signed-off-by: Juri Lelli Acked-by: Peter Zijlstra (Intel) Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20180213185519.18186-2-juri.lelli@redhat.com Signed-off-by: Ingo Molnar

Documentation/locking/mutex-design: Update to reflect latest changes

2018-02-11T11:28:58Z

Commit 3ca0ff571b09 ("locking/mutex: Rework mutex::owner") reworked the basic mutex implementation to deal with several problems. Documentation was however left unchanged and became stale. Update mutex-design.txt to reflect changes introduced by the above commit. Signed-off-by: Juri Lelli Cc: Andrew Morton Cc: Davidlohr Bueso Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20180209160114.19980-1-juri.lelli@redhat.com [ Small readability tweaks to the text. ] Signed-off-by: Ingo Molnar

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2018-01-03T13:14:18Z

Pull RCU updates from Paul E. McKenney: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Miscellaneous fixes. - Torture-test updates. Signed-off-by: Ingo Molnar