On 15/07/2023 01:04, John Hubbard wrote: > On 7/13/23 06:54, Ryan Roberts wrote: >> arm64 does not support the soft-dirty PTE bit. However there are tests >> in `madv_populate` and `soft-dirty` which assume it is supported and >> cause spurious failures to be reported when preferred behaviour would be >> to mark the tests as skipped. >> >> Unfortunately, the only way to determine if the soft-dirty dirty bit is >> supported is to write to a page, then see if the bit is set in >> /proc/self/pagemap. But the tests that we want to conditionally execute >> are testing precicesly this. So if we introduced this feature check, we >> could accedentally turn a real failure (on a system that claims to >> support soft-dirty) into a skip. > > ... > >> diff --git a/tools/testing/selftests/mm/soft-dirty.c >> b/tools/testing/selftests/mm/soft-dirty.c >> index cc5f144430d4..8a2cd161ec4d 100644 >> --- a/tools/testing/selftests/mm/soft-dirty.c >> +++ b/tools/testing/selftests/mm/soft-dirty.c > > Hi Ryan, > > Probably very similar to what David is requesting: given that arm64 > definitively does not support soft dirty, I'd suggest that we not even > *build* the soft dirty tests on arm64! > > There is no need to worry about counting, skipping or waiving such > tests, either. Because it's just a non-issue: one does not care about > test status for something that is documented as "this feature is simply > unavailable here". OK fair enough. I'll follow this approach for v2. Thanks for the review! > > > thanks,
