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Groups > linux.kernel > #1499880
| From | Davidlohr Bueso <dave@stgolabs.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH -v4 2/8] locking/mutex: Rework mutex::owner |
| Date | 2016-10-12 20:40 +0200 |
| Message-ID | <srwBA-8aY-43@gated-at.bofh.it> (permalink) |
| References | <spEWB-2dt-5@gated-at.bofh.it> <spFfY-2lv-63@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, 07 Oct 2016, Peter Zijlstra wrote:
>+/*
>+ * Optimistic trylock that only works in the uncontended case. Make sure to
>+ * follow with a __mutex_trylock() before failing.
>+ */
>+static __always_inline bool __mutex_trylock_fast(struct mutex *lock)
>+{
>+ unsigned long curr = (unsigned long)current;
>+
>+ if (!atomic_long_cmpxchg_acquire(&lock->owner, 0UL, curr))
>+ return true;
Do we want to do a ccas check for !lock->owner? Although I can see a possible
case of 'optimizing for the contended' reasons for nay.
Thanks,
Davidlohr
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[PATCH -v4 0/8] locking/mutex: Rewrite basic mutex Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:10 +0200
[PATCH -v4 4/8] locking/mutex: Allow MUTEX_SPIN_ON_OWNER when DEBUG_MUTEXES Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:10 +0200
[PATCH -v4 7/8] locking/mutex: Simplify some ww_mutex code in __mutex_lock_common() Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:10 +0200
[PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:30 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Will Deacon <will.deacon@arm.com> - 2016-10-13 17:20 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-17 12:50 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-17 15:30 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Boqun Feng <boqun.feng@gmail.com> - 2016-10-17 15:50 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-17 18:00 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-19 19:40 +0200
ciao set_task_state() (was Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop) Davidlohr Bueso <dave@stgolabs.net> - 2016-10-24 04:00 +0200
Re: ciao set_task_state() (was Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop) Kent Overstreet <kent.overstreet@gmail.com> - 2016-10-24 15:30 +0200
Re: ciao set_task_state() (was Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop) Kent Overstreet <kent.overstreet@gmail.com> - 2016-10-24 16:30 +0200
Re: ciao set_task_state() (was Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop) Eric Wheeler <bcache@lists.ewheeler.net> - 2016-10-25 19:00 +0200
Re: ciao set_task_state() (was Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop) Kent Overstreet <kent.overstreet@gmail.com> - 2016-10-25 19:50 +0200
Re: [PATCH -v4 6/8] locking/mutex: Restructure wait loop Peter Zijlstra <peterz@infradead.org> - 2016-10-18 15:20 +0200
[PATCH -v4 8/8] locking/mutex: Enable optimistic spinning of woken waiter Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:30 +0200
Re: [PATCH -v4 8/8] locking/mutex: Enable optimistic spinning of woken waiter Will Deacon <will.deacon@arm.com> - 2016-10-13 17:30 +0200
Re: [PATCH -v4 8/8] locking/mutex: Enable optimistic spinning of woken waiter Peter Zijlstra <peterz@infradead.org> - 2016-10-17 11:40 +0200
Re: [PATCH -v4 8/8] locking/mutex: Enable optimistic spinning of woken waiter Peter Zijlstra <peterz@infradead.org> - 2016-10-18 14:30 +0200
[PATCH -v4 2/8] locking/mutex: Rework mutex::owner Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:30 +0200
Re: [PATCH -v4 2/8] locking/mutex: Rework mutex::owner Davidlohr Bueso <dave@stgolabs.net> - 2016-10-12 20:40 +0200
Re: [PATCH -v4 2/8] locking/mutex: Rework mutex::owner Jason Low <jason.low2@hpe.com> - 2016-10-12 22:00 +0200
Re: [PATCH -v4 2/8] locking/mutex: Rework mutex::owner Will Deacon <will.deacon@arm.com> - 2016-10-13 17:20 +0200
[PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid starvation Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:40 +0200
Re: [PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid starvation Will Deacon <will.deacon@arm.com> - 2016-10-13 17:20 +0200
Re: [PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid starvation Peter Zijlstra <peterz@infradead.org> - 2016-10-17 11:30 +0200
Re: [PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid starvation Peter Zijlstra <peterz@infradead.org> - 2016-10-18 14:40 +0200
Re: [PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid starvation Peter Zijlstra <peterz@infradead.org> - 2016-10-18 15:10 +0200
[PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:40 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:50 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 18:00 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-07 18:20 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Thomas Gleixner <tglx@linutronix.de> - 2016-10-08 14:10 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Thomas Gleixner <tglx@linutronix.de> - 2016-10-08 16:20 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-08 18:50 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-08 16:20 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-18 14:50 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Peter Zijlstra <peterz@infradead.org> - 2016-10-18 15:00 +0200
Re: [PATCH -v4 1/8] locking/drm: Kill mutex trickery Chris Wilson <chris@chris-wilson.co.uk> - 2016-10-18 15:00 +0200
[PATCH -v4 3/8] locking/mutex: Kill arch specific code Peter Zijlstra <peterz@infradead.org> - 2016-10-07 17:40 +0200
Re: [PATCH -v4 0/8] locking/mutex: Rewrite basic mutex Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 17:50 +0200
Re: [PATCH -v4 0/8] locking/mutex: Rewrite basic mutex Jason Low <jason.low2@hpe.com> - 2016-10-11 21:10 +0200
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