On Thu, 26 Nov 2015, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > On Thu, Nov 26, 2015 at 03:49:00PM +0100, Daniel Vetter wrote: >> On Thu, Nov 26, 2015 at 01:31:42PM +0000, Chris Wilson wrote: >> > We have relied upon the sole caller (wait_ioctl) validating the timeout >> > argument. However, when waiting for multiple requests I forgot to ensure >> > that the timeout was still positive on the later requests. This is more >> > simply done inside __i915_wait_request. >> > >> > Fixes regression introduced in >> > commit b47161858ba13c9c7e03333132230d66e008dd55 >> > Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> > Date: Mon Apr 27 13:41:17 2015 +0100 >> > >> > drm/i915: Implement inter-engine read-read optimisations >> > >> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> > Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxxxxxxxx> >> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> >> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> >> > Cc: stable@xxxxxxxxxxxxxxx >> >> Commit message should explain what the actual problem is - we add 1 jiffy >> of delay for each wait_request, potentially waiting quite a bit longer >> than what userspace asked for. >> >> And not sure this really justifies for cc: stable, since all the wait >> syscalls reserve the right to wait longer. Of course we should fix it, >> just to keep validating this possible. > > Dropping stable is fine, that was just a knee jerk reaction to finding a > regression. The impact is 1 jiffie for each extra active ring for a > wait_ioctl with a timeout -- I don't think anyone has noticed. Pushed to drm-intel-fixes with some random copy-paste added about the 1 jiffy. Thanks for the patch and review. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
