Re: [PATCH] mutex: Remove ww_ctx unlikely() from __mutex_lock_common()

2017-01-19 Thread Peter Zijlstra
On Thu, Jan 19, 2017 at 08:54:41AM -0500, Steven Rostedt (VMware) wrote: > I added a comment stating that the branch should be unlikely, but due > to the intel drm logic, it currently isn't. Then if drm changes in the > future, we could then try it again. I really don't see the point here. The unl

Re: [PATCH] mutex: Remove ww_ctx unlikely() from __mutex_lock_common()

2017-01-19 Thread Steven Rostedt
On Thu, 19 Jan 2017 17:42:52 +0100 Peter Zijlstra wrote: > On Thu, Jan 19, 2017 at 08:54:41AM -0500, Steven Rostedt (VMware) wrote: > > I added a comment stating that the branch should be unlikely, but due > > to the intel drm logic, it currently isn't. Then if drm changes in the > > future, we c

[PATCH] mutex: Remove ww_ctx unlikely() from __mutex_lock_common()

2017-01-19 Thread Steven Rostedt (VMware)
The unikely() used in __mutex_lock_common() when use_ww_ctx is set is currently dependent on the hardware if it is likely or unlikely. The intel drm code calls into this function and triggers this branch 100% of the time. As this hardware is very commonly used, this is not a rare case at all (the