From: John Harrison <John.C.Harrison@xxxxxxxxx> The context persistence code does things like send super high priority heartbeat pulses to ensure any leaked context can still be pre-empted and thus isn't a total denial of service but only a minor denial of service. Unfortunately, it wasn't bothering to restart the heatbeat worker with a fresh timeout. Thus, if a persistent context happened to be closed just before the heartbeat was going to go ping anyway then the forced pulse would get a negligble execution time. And as the forced pulse is super high priority, the worker thread's next step is a reset. Which means a potentially innocent system randomly goes boom when attempting to close a context. So, force a re-schedule of the worker thread with the appropriate timeout. Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index 1a8e2b7db0138..4ae2fa0b61dd4 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -290,6 +290,9 @@ static int __intel_engine_pulse(struct intel_engine_cs *engine) heartbeat_commit(rq, &attr); GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER); + /* Ensure the forced pulse gets a full period to execute */ + next_heartbeat(engine); + return 0; } -- 2.43.0
