On Wed, 31 Oct 2012 17:18:47 -0700, Eric Anholt <eric at anholt.net> wrote: > ville.syrjala at linux.intel.com writes: > > > From: Ville Syrj??l?? <ville.syrjala at linux.intel.com> > > > > As per Chris Wilson's suggestion make > > i915_gem_execbuffer_wait_for_flips() go away. > > > > This was used to stall the GPU ring while there are pending > > page flips involving the relevant BO. Ie. while the BO is still > > being scanned out by the display controller. > > > > The recommended alternative is to use the page flip events to > > wait for the page flips to fully complete before reusing the BO > > of the old front buffer. Or use more buffers. > > So, after this change, if userland submits an execbuf between having > requested a pageflip and the vblank that the flip shows up on, does that > exec block? The code itself is dysfunctional and would cause a GPU hang on snb/ivb. Why should the kernel be imposing a policy upon userspace where none is required? -Chris -- Chris Wilson, Intel Open Source Technology Centre
