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Groups > linux.kernel > #1407514
| From | Chris Wilson <chris@chris-wilson.co.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance |
| Date | 2016-05-26 12:50 +0200 |
| Message-ID | <rD11w-5kZ-15@gated-at.bofh.it> (permalink) |
| References | <rCYZH-45r-9@gated-at.bofh.it> <rD0RP-5hu-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, May 26, 2016 at 12:37:30PM +0200, Maarten Lankhorst wrote: > The check should also not be for NULL, but for use_ww_ctx. > This way the if check is optimized out for the ww_ctx path, where > ww_ctx is always non-null. The compiler can see use_ww_ctx == false => ww_ctx == NULL just as well to do dead-code elimination, i.e. use_ww_ctx is superflouus and does not reduce the code size. (gcc 4.7.2, 4.9.1, 5.3.1) -Chris -- Chris Wilson, Intel Open Source Technology Centre
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[PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance Chris Wilson <chris@chris-wilson.co.uk> - 2016-05-26 10:40 +0200
Re: [PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2016-05-26 12:40 +0200
Re: [PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance Chris Wilson <chris@chris-wilson.co.uk> - 2016-05-26 12:50 +0200
Re: [PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2016-05-26 13:10 +0200
[PATCH] mutex: Report recursive ww_mutex locking early Chris Wilson <chris@chris-wilson.co.uk> - 2016-05-26 22:10 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2016-05-30 09:50 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Peter Zijlstra <peterz@infradead.org> - 2016-05-30 11:20 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2016-05-30 11:50 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Peter Zijlstra <peterz@infradead.org> - 2016-05-30 12:30 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Chris Wilson <chris@chris-wilson.co.uk> - 2016-05-30 12:50 +0200
Re: [PATCH] mutex: Report recursive ww_mutex locking early Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2016-05-30 13:20 +0200
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