Messages in this thread | | | Date | Thu, 26 May 2016 11:43:29 +0100 | From | Chris Wilson <> | Subject | Re: [PATCH] mutex: Do not spin/queue before performing ww_mutex deadlock avoidance |
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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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