Quoting Andi Shyti (2021-01-08 13:51:54) > Hi Chris, > > > > > diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c > > > > b/drivers/gpu/drm/i915/selftests/intel_memory_region.c > > > > index 75839db63bea..59c58a276677 100644 > > > > --- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c > > > > +++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c > > > > @@ -852,6 +852,9 @@ static int _perf_memcpy(struct intel_memory_region > > > > *src_mr, > > > > } > > > > > > > > sort(t, ARRAY_SIZE(t), sizeof(*t), wrap_ktime_compare, > > > > NULL); > > > > + if (!t[0]) > > > > + continue; > > > > + > > > > > > are you assuming here that if t[0] is '0', also the rest of 't' > > > is '0'? > > > > It's sorted into ascending order with ktime_t... Hmm, s64 not u64 as I > > presumed. So better to check <= 0. > > by division by 0 I guess you mean here: > > div64_u64(mul_u32_u32(4 * size, > 1000 * 1000 * 1000), > t[1] + 2 * t[2] + t[3]) >> 20); > > why are you testing t[0]? Did I miss anything else?
Since t[0] is the most negative value, if it is <= 0 that implies at least one of the measurements was bad. If any are bad, all are bad by association. I considered checking t[4] to make sure that at least the best was good enough, but paranoia won. -Chris _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
