From c318a203eade42cae639b2bc50c95d1f7d132db4 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 8 Jan 2021 20:40:21 +0000 Subject: [PATCH] drm/i915/selftests: Skip unstable timing measurements If any of the perf tests run into 0 time, not only are we liable to divide by zero, but the result would be highly questionable. Nevertheless, let's not have a div-by-zero error. Signed-off-by: Chris Wilson Cc: Andi Shyti Reviewed-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20210108204026.20682-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/selftests/intel_memory_region.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c index 75839db..ce7adfa 100644 --- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c +++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c @@ -852,14 +852,22 @@ static int _perf_memcpy(struct intel_memory_region *src_mr, } sort(t, ARRAY_SIZE(t), sizeof(*t), wrap_ktime_compare, NULL); + if (t[0] <= 0) { + /* ignore the impossible to protect our sanity */ + pr_debug("Skipping %s src(%s, %s) -> dst(%s, %s) %14s %4lluKiB copy, unstable measurement [%lld, %lld]\n", + __func__, + src_mr->name, repr_type(src_type), + dst_mr->name, repr_type(dst_type), + tests[i].name, size >> 10, + t[0], t[4]); + continue; + } + pr_info("%s src(%s, %s) -> dst(%s, %s) %14s %4llu KiB copy: %5lld MiB/s\n", __func__, - src_mr->name, - repr_type(src_type), - dst_mr->name, - repr_type(dst_type), - tests[i].name, - size >> 10, + src_mr->name, repr_type(src_type), + dst_mr->name, repr_type(dst_type), + tests[i].name, size >> 10, div64_u64(mul_u32_u32(4 * size, 1000 * 1000 * 1000), t[1] + 2 * t[2] + t[3]) >> 20); -- 2.7.4