Quoting Lionel Landwerlin (2018-05-11 16:43:02) > On 11/05/18 15:18, Chris Wilson wrote: > > Quoting Lionel Landwerlin (2018-05-11 15:14:13) > >> My understanding of the virtual memory addressing from the GPU is limited... > >> But how can the GPU poke at the kernel's allocated data? > >> I thought we mapped into the GPU's address space only what is allocated > >> through gem. > > Correct. The HW should only be accessing the pages through the GTT and > > the GTT should only contain known pages (or a pointer to the scratch > > page). There is maybe a hole where we are freeing the memory before > > the HW has finished using it (still writing through stale TLB and > > whatnot even though the system has reallocated the pages), but other > > than that quite, quite scary. Hence this awooga. > > > > I managed to reproduce a kasan backtrace on the same test. > So it's not just the CI machine. For the record, CI also seems much happier with the wait for OACONTROL before unpinning, so no need to panic! -Chris
