Quoting Matthew Auld (2018-05-10 22:12:13) > On 10 May 2018 at 20:56, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > Quoting Matthew Auld (2018-05-10 20:00:06) > >> We write out all PTEs when operating in 64K mode, which is acceptable > >> given the assertion that the hw only cares about every 16th PTE and so > >> will ignore everything else. However this may hide potential issues, > >> for example the hw could be sneakily operating in 4K mode and we would > >> be none the wiser, so make sure this doesn't escape us in the selftests. > > > > For selftesting, don't you want to do the opposite and set the ignored > > addresses to something that will explode, and not something safe? > > The tests will fail, when we do write_huge some of our writes will > land in scratch, and cpu_check will throw a fit. >From reading the comment I was mightily confused, the commitmsg is better for it included an extra clause of explanation. /* * We write all 4K page entries, even when using 64K pages. In order * to verify that the HW isn't cheating by using the 4K PTE instead * of the 64K PTE, we want to remove all the surplus entries. If the HW * skipped the 64K PTE, it will read/write into the scratch page instead - * which we detect as missing results during selftests. */ -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
