On Thu, Nov 26, 2015 at 04:51:13PM +0100, Daniel Vetter wrote: > On Thu, Nov 26, 2015 at 03:34:05PM +0000, Chris Wilson wrote: > > On Thu, Nov 26, 2015 at 03:46:06PM +0100, Daniel Vetter wrote: > > > On Thu, Nov 26, 2015 at 12:59:37PM +0000, Chris Wilson wrote: > > > > On Thu, Nov 26, 2015 at 12:34:35PM +0100, Daniel Vetter wrote: > > > > > Since $debugfs/i915_wedged restores a wedged gpu by using a normal gpu > > > > > hang we need to be careful to not run into the "hanging too fast > > > > > check": > > > > > > > > > > - don't restore the ban period, but instead keep it at 0. > > > > > - make sure we idle the gpu fully before hanging it again (wait > > > > > subtest missted that). > > > > > > > > > > With this gem_eio works now reliable even when I don't run the > > > > > subtests individually. > > > > > > > > > > Of course it's a bit fishy that the default ctx gets blamed for > > > > > essentially doing nothing, but until that's figured out in upstream > > > > > it's better to make the test work for now. > > > > > > > > This used to be reliable. And just disabling all banning in the kernel > > > > forever more is silly. > > > > > > > > During igt_post_hang_ring: > > > > 1. we wait upon the hanging batch > > > > - this returns when hangcheck fires > > > > 2. reset the ban period to normal > > > > - this takes mutex_lock_interruptible and so must wait for the reset > > > > handler to run before it can make the change, > > > > - ergo the hanging batch never triggers a ban for itself. > > > > - (a subsequent nonsimulated GPU hang may trigger the ban though) > > > > > > This isn't where it dies. It dies when we do the echo 1 > i915_wedged. > > > > That is not where it dies. > > Well at least it happens after we start the hang recover from i915_wedged. > > > > I suspect quiescent_gpu or whatever is getting in the way, but I really only > > > wanted to get things to run first. And since i915_wedged is a developer > > > feature, and it does work perfectly if you don't intend to reuse contexts > > > I didn't see any point in first trying to fix it up. > > > > > > So I still maintain that this is a good enough approach, at least if > > > there's no obvious fix in-flight already. > > > > No way. This is a kernel regression since 4.0, having just tested with > > v4.0 on snb/ivb/hsw. > > Ok, I didn't realize that. I figured since i915_wedged will return -EAGAIN > anyway when we are terminally wedged, and that seems to have been the case > ever since we started with reset_counter this has been broken forever. I > guess I missed something. The bug I see is SNB specific, and introduced between v4.0 and v4.1. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
