On Wed, Mar 26, 2014 at 08:06:00AM -0700, Ben Widawsky wrote: > On Wed, Mar 26, 2014 at 08:04:38AM +0100, Daniel Vetter wrote: > > On Wed, Mar 26, 2014 at 07:24:16AM +0100, Daniel Vetter wrote: > > > On Tue, Mar 25, 2014 at 07:01:50PM -0700, Ben Widawsky wrote: > > > > While the context is not being used, we can make the PTEs invalid, so > > > > nothing can accidentally corrupt it. Systems tend to have a lot of > > > > trouble when the context gets corrupted. > > > > > > > > NOTE: This is a slightly different patch than what I posted to Bugzilla. > > > > > > > > References: https://bugs.freedesktop.org/show_bug.cgi?id=75724 > > > > Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx> > > > > > > We could stop the aliasing ppgtt binder from always binding into the > > > ppgtt. Which is the bug I'm signed up to fix, and which probably curbs 99% > > > of all potential corruption. The last 1% is the kernel getting his > > > kmapping wrong ... > > > > Actually your patch doesn't accomplish much, since MI_UPDATE_GTT only > > updates the global gtt, not the aliasing ppgtt. Which means that userspace > > batches can still happily stomp all over your precious context objects. > > See comment #5 in that bug report: > > > > https://bugs.freedesktop.org/show_bug.cgi?id=75724#c5 > > > > Cheers, Daniel > > Quoting you from comment #5: > "ctx objects should only be bound in the global gtt with aliasing > ppgtt." > > The bug was not present with full PPGTT. > Oh, I see the confusion. I don't necessarily think it's userspace that's corrupting this. I just want to prove it's *not* being corrupted. -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
