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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2021-01-13 19:31:15 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2021-01-14 01:14:41 +0300 |
| commit | 81746b74c1e7cb1c4b77465e0a7434f2c33464d2 (patch) | |
| tree | dd6bd49eb5e7b79fd8c7ffcf2494007f4e05991e /drivers | |
| parent | 106a9368dc679d7de41a4d63760405bd2a58fd29 (diff) | |
| download | linux-81746b74c1e7cb1c4b77465e0a7434f2c33464d2.tar.xz | |
drm/i915/selftests: Bump the scheduling error threshold for fast heartbeats
Since we are system_highpri_wq, we expected the heartbeat to be
scheduled promptly. However, we see delays of over 10ms upsetting our
assertions. Accept this as inevitable and bump the minimum error
threshold to 20ms (from 6 jiffies).
<6> [616.784749] rcs0: Heartbeat delay: 3570us [2802, 9188]
<6> [616.807790] bcs0: Heartbeat delay: 2111us [745, 4372]
<6> [616.853776] vcs0: Heartbeat delay: 6485us [2424, 11637]
<3> [616.859296] vcs0: Heartbeat delay was 6485us, expected less than 6000us
<3> [616.860901] i915/intel_heartbeat_live_selftests: live_heartbeat_fast failed with error -22
v2: More context from CI.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210113163115.5740-2-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c index b88aa35ad75b..223ab88f7e57 100644 --- a/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c @@ -197,6 +197,7 @@ static int cmp_u32(const void *_a, const void *_b) static int __live_heartbeat_fast(struct intel_engine_cs *engine) { + const unsigned int error_threshold = max(20000u, jiffies_to_usecs(6)); struct intel_context *ce; struct i915_request *rq; ktime_t t0, t1; @@ -254,12 +255,18 @@ static int __live_heartbeat_fast(struct intel_engine_cs *engine) times[0], times[ARRAY_SIZE(times) - 1]); - /* Min work delay is 2 * 2 (worst), +1 for scheduling, +1 for slack */ - if (times[ARRAY_SIZE(times) / 2] > jiffies_to_usecs(6)) { + /* + * Ideally, the upper bound on min work delay would be something like + * 2 * 2 (worst), +1 for scheduling, +1 for slack. In practice, we + * are, even with system_wq_highpri, at the mercy of the CPU scheduler + * and may be stuck behind some slow work for many millisecond. Such + * as our very own display workers. + */ + if (times[ARRAY_SIZE(times) / 2] > error_threshold) { pr_err("%s: Heartbeat delay was %uus, expected less than %dus\n", engine->name, times[ARRAY_SIZE(times) / 2], - jiffies_to_usecs(6)); + error_threshold); err = -EINVAL; } |