On Thu, Jan 21, 2016 at 01:51:30PM +0000, Tvrtko Ursulin wrote: > But I can't really figure where would you put this poisoning? You > could put something in in exec list mode after context complete and > check it before it is used next time, I was thinking just in context-free. Move the pages to a poisoned list and check at the end of the test. The issue is that the GPU may write to the pages as we release them, so instead of releasing them we just poison them (or CRC them). > but I did not think we can hit > this in exec list mode, only in GuC. You think it is possible? With the current code, no since the last context unreference is done from i915_gem_request_free(), and the request reference is only dropped after we see the context-switch/active->idle state change (i.e. the context save should always be flushed by the time we unpin and free the context). However, that ordering imposes the struct_mutex upon request-free which leads to fairly severe issues that can be eleviated by moving the context-unreference into the request-retire - which opens up the context-close race to normal execlists, as the context can be unreferenced before the next context-switch-interrupt, now fixed in this patch. And reducing the context-pin lifetime even further should help mitigate context thrashing and certain userspace stress tests (OpenGL microbenchmarks). -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
