On Tue, Nov 04, 2014 at 03:14:04PM +0000, Tvrtko Ursulin wrote: > > On 11/04/2014 02:31 PM, Chris Wilson wrote: > >Running __mmu_notifier_register() is surprisingly expensive, so let's > >not do that unless we have to. > > Affects some program startup or what? What is the cost? I would add > some notes in the commit for future reference.
It was affecting a badly behavely igt test, that was provoking the linear walk in mm_take_all_locks() and then causing each one to restart due to signals... Performance fell off a cliff. This was extreme, but one can suppose that on a similarly stressed system startup performance will also degrade. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
