diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-06-17 14:09:16 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-06-18 09:26:54 +0100 |
| commit | 810b7ee3008ab2ac94791f75857815484c2f9cce (patch) | |
| tree | 85ff11b677567a5670ccd63e5ba00a1d22994c81 /drivers/gpu/drm/i915/gt/selftest_engine_pm.c | |
| parent | 1b90e4a43b7444fc4159c6dd338a44e8808e8718 (diff) | |
drm/i915/gt: Always report the sample time for busy-stats
Return the monotonic timestamp (ktime_get()) at the time of sampling the
busy-time. This is used in preference to taking ktime_get() separately
before or after the read seqlock as there can be some large variance in
reported timestamps. For selftests trying to ascertain that we are
reporting accurate to within a few microseconds, even a small delay
leads to the test failing.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200617130916.15261-2-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt/selftest_engine_pm.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_engine_pm.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c index dd54dcb5cca2..b08fc5390e8a 100644 --- a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c +++ b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c @@ -29,8 +29,8 @@ static int live_engine_busy_stats(void *arg) GEM_BUG_ON(intel_gt_pm_is_awake(gt)); for_each_engine(engine, gt, id) { struct i915_request *rq; - ktime_t de; - u64 dt; + ktime_t de, dt; + ktime_t t[2]; if (!intel_engine_supports_stats(engine)) continue; @@ -47,12 +47,11 @@ static int live_engine_busy_stats(void *arg) ENGINE_TRACE(engine, "measuring idle time\n"); preempt_disable(); - dt = ktime_to_ns(ktime_get()); - de = intel_engine_get_busy_time(engine); + de = intel_engine_get_busy_time(engine, &t[0]); udelay(100); - de = ktime_sub(intel_engine_get_busy_time(engine), de); - dt = ktime_to_ns(ktime_get()) - dt; + de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de); preempt_enable(); + dt = ktime_sub(t[1], t[0]); if (de < 0 || de > 10) { pr_err("%s: reported %lldns [%d%%] busyness while sleeping [for %lldns]\n", engine->name, @@ -80,12 +79,11 @@ static int live_engine_busy_stats(void *arg) ENGINE_TRACE(engine, "measuring busy time\n"); preempt_disable(); - dt = ktime_to_ns(ktime_get()); - de = intel_engine_get_busy_time(engine); + de = intel_engine_get_busy_time(engine, &t[0]); udelay(100); - de = ktime_sub(intel_engine_get_busy_time(engine), de); - dt = ktime_to_ns(ktime_get()) - dt; + de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de); preempt_enable(); + dt = ktime_sub(t[1], t[0]); if (100 * de < 95 * dt || 95 * de > 100 * dt) { pr_err("%s: reported %lldns [%d%%] busyness while spinning [for %lldns]\n", engine->name, |