[PATCH v2 1/3] drm/i915: Cancel outstanding work after disabling heartbeats on an engine
We only allow persistent requests to remain on the GPU past the closure of their containing context (and process) so long as they are continuously checked for hangs or allow other requests to preempt them, as we need to ensure forward progress of the system. If we allow persistent contexts to remain on the system after the the hangcheck mechanism is disabled, the system may grind to a halt. On disabling the mechanism, we sent a pulse along the engine to remove all executing contexts from the engine which would check for hung contexts -- but we did not prevent those contexts from being resubmitted if they survived the final hangcheck.
Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs") Testcase: igt/gem_ctx_persistence/heartbeat-stop Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com --- drivers/gpu/drm/i915/gt/intel_engine.h | 9 +++++++++ drivers/gpu/drm/i915/i915_request.c | 5 +++++ 2 files changed, 14 insertions(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h index 08e2c000dcc3..7c3a1012e702 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine.h +++ b/drivers/gpu/drm/i915/gt/intel_engine.h @@ -337,4 +337,13 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine) return intel_engine_has_preemption(engine); }
+static inline bool +intel_engine_has_heartbeat(const struct intel_engine_cs *engine) +{ + if (!IS_ACTIVE(CONFIG_DRM_I915_HEARTBEAT_INTERVAL)) + return false; + + return READ_ONCE(engine->props.heartbeat_interval_ms); +} + #endif /* _INTEL_RINGBUFFER_H_ */ diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 436ce368ddaa..0e813819b041 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -542,8 +542,13 @@ bool __i915_request_submit(struct i915_request *request) if (i915_request_completed(request)) goto xfer;
+ if (unlikely(intel_context_is_closed(request->context) && + !intel_engine_has_heartbeat(engine))) + intel_context_set_banned(request->context); + if (unlikely(intel_context_is_banned(request->context))) i915_request_set_error_once(request, -EIO); + if (unlikely(fatal_error(request->fence.error))) __i915_request_skip(request);
Currently, we check we can send a pulse prior to disabling the heartbeat to verify that we can change the heartbeat, but since we may re-evaluate execution upon changing the heartbeat interval we need another pulse afterwards to refresh execution.
v2: Tvrtko asked if we could reduce the double pulse to a single, which opened up a discussion of how we should handle the pulse-error after attempting to change the property, and the desire to serialise adjustment of the property with its validating pulse, and unwind upon failure.
Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: stable@vger.kernel.org # v5.7+ --- .../gpu/drm/i915/gt/intel_engine_heartbeat.c | 105 +++++++++++------- 1 file changed, 66 insertions(+), 39 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index 8ffdf676c0a0..eda475f50fa7 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -177,36 +177,81 @@ void intel_engine_init_heartbeat(struct intel_engine_cs *engine) INIT_DELAYED_WORK(&engine->heartbeat.work, heartbeat); }
+static int __intel_engine_pulse(struct intel_engine_cs *engine) +{ + struct i915_sched_attr attr = { .priority = I915_PRIORITY_BARRIER }; + struct intel_context *ce = engine->kernel_context; + struct i915_request *rq; + + lockdep_assert_held(&ce->timeline->mutex); + GEM_BUG_ON(intel_engine_has_preemption(engine)); + GEM_BUG_ON(intel_engine_pm_is_awake(engine)); + + intel_context_enter(ce); + rq = __i915_request_create(ce, GFP_NOWAIT | __GFP_NOWARN); + intel_context_exit(ce); + if (IS_ERR(rq)) + return PTR_ERR(rq); + + __set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags); + idle_pulse(engine, rq); + + __i915_request_commit(rq); + __i915_request_queue(rq, &attr); + GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER); + + return 0; +} + +static unsigned long set_heartbeat(struct intel_engine_cs *engine, + unsigned long delay) +{ + unsigned long old; + + old = xchg(&engine->props.heartbeat_interval_ms, delay); + if (delay) + intel_engine_unpark_heartbeat(engine); + else + intel_engine_park_heartbeat(engine); + + return old; +} + int intel_engine_set_heartbeat(struct intel_engine_cs *engine, unsigned long delay) { - int err; + struct intel_context *ce = engine->kernel_context; + int err = 0;
- /* Send one last pulse before to cleanup persistent hogs */ - if (!delay && IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT)) { - err = intel_engine_pulse(engine); - if (err) - return err; - } + if (!delay && !intel_engine_has_preempt_reset(engine)) + return -ENODEV; + + intel_engine_pm_get(engine); + + err = mutex_lock_interruptible(&ce->timeline->mutex); + if (err) + return err;
- WRITE_ONCE(engine->props.heartbeat_interval_ms, delay); + if (delay != engine->props.heartbeat_interval_ms) { + unsigned long saved = set_heartbeat(engine, delay);
- if (intel_engine_pm_get_if_awake(engine)) { - if (delay) - intel_engine_unpark_heartbeat(engine); - else - intel_engine_park_heartbeat(engine); - intel_engine_pm_put(engine); + /* recheck current execution */ + if (intel_engine_has_preemption(engine)) { + err = __intel_engine_pulse(engine); + if (err) + set_heartbeat(engine, saved); + } }
- return 0; + mutex_unlock(&ce->timeline->mutex); + intel_engine_pm_put(engine); + + return err; }
int intel_engine_pulse(struct intel_engine_cs *engine) { - struct i915_sched_attr attr = { .priority = I915_PRIORITY_BARRIER }; struct intel_context *ce = engine->kernel_context; - struct i915_request *rq; int err;
if (!intel_engine_has_preemption(engine)) @@ -215,30 +260,12 @@ int intel_engine_pulse(struct intel_engine_cs *engine) if (!intel_engine_pm_get_if_awake(engine)) return 0;
- if (mutex_lock_interruptible(&ce->timeline->mutex)) { - err = -EINTR; - goto out_rpm; + err = -EINTR; + if (!mutex_lock_interruptible(&ce->timeline->mutex)) { + err = __intel_engine_pulse(engine); + mutex_unlock(&ce->timeline->mutex); }
- intel_context_enter(ce); - rq = __i915_request_create(ce, GFP_NOWAIT | __GFP_NOWARN); - intel_context_exit(ce); - if (IS_ERR(rq)) { - err = PTR_ERR(rq); - goto out_unlock; - } - - __set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags); - idle_pulse(engine, rq); - - __i915_request_commit(rq); - __i915_request_queue(rq, &attr); - GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER); - err = 0; - -out_unlock: - mutex_unlock(&ce->timeline->mutex); -out_rpm: intel_engine_pm_put(engine); return err; }
On 28/09/2020 13:12, Chris Wilson wrote:
Currently, we check we can send a pulse prior to disabling the heartbeat to verify that we can change the heartbeat, but since we may re-evaluate execution upon changing the heartbeat interval we need another pulse afterwards to refresh execution.
v2: Tvrtko asked if we could reduce the double pulse to a single, which opened up a discussion of how we should handle the pulse-error after attempting to change the property, and the desire to serialise adjustment of the property with its validating pulse, and unwind upon failure.
Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: stable@vger.kernel.org # v5.7+
.../gpu/drm/i915/gt/intel_engine_heartbeat.c | 105 +++++++++++------- 1 file changed, 66 insertions(+), 39 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index 8ffdf676c0a0..eda475f50fa7 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -177,36 +177,81 @@ void intel_engine_init_heartbeat(struct intel_engine_cs *engine) INIT_DELAYED_WORK(&engine->heartbeat.work, heartbeat); } +static int __intel_engine_pulse(struct intel_engine_cs *engine) +{
- struct i915_sched_attr attr = { .priority = I915_PRIORITY_BARRIER };
- struct intel_context *ce = engine->kernel_context;
- struct i915_request *rq;
- lockdep_assert_held(&ce->timeline->mutex);
- GEM_BUG_ON(intel_engine_has_preemption(engine));
- GEM_BUG_ON(intel_engine_pm_is_awake(engine));
- intel_context_enter(ce);
- rq = __i915_request_create(ce, GFP_NOWAIT | __GFP_NOWARN);
- intel_context_exit(ce);
- if (IS_ERR(rq))
return PTR_ERR(rq);- __set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags);
- idle_pulse(engine, rq);
- __i915_request_commit(rq);
- __i915_request_queue(rq, &attr);
- GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER);
- return 0;
+}
+static unsigned long set_heartbeat(struct intel_engine_cs *engine,
unsigned long delay)+{
- unsigned long old;
- old = xchg(&engine->props.heartbeat_interval_ms, delay);
- if (delay)
intel_engine_unpark_heartbeat(engine);- else
intel_engine_park_heartbeat(engine);- return old;
+}
- int intel_engine_set_heartbeat(struct intel_engine_cs *engine, unsigned long delay) {
- int err;
- struct intel_context *ce = engine->kernel_context;
- int err = 0;
- /* Send one last pulse before to cleanup persistent hogs */
- if (!delay && IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT)) {
err = intel_engine_pulse(engine);if (err)return err;- }
- if (!delay && !intel_engine_has_preempt_reset(engine))
return -ENODEV;- intel_engine_pm_get(engine);
- err = mutex_lock_interruptible(&ce->timeline->mutex);
- if (err)
return err;
- WRITE_ONCE(engine->props.heartbeat_interval_ms, delay);
- if (delay != engine->props.heartbeat_interval_ms) {
unsigned long saved = set_heartbeat(engine, delay);
- if (intel_engine_pm_get_if_awake(engine)) {
if (delay)intel_engine_unpark_heartbeat(engine);elseintel_engine_park_heartbeat(engine);intel_engine_pm_put(engine);
/* recheck current execution */if (intel_engine_has_preemption(engine)) {err = __intel_engine_pulse(engine);if (err)set_heartbeat(engine, saved);}
- return 0;
- mutex_unlock(&ce->timeline->mutex);
- intel_engine_pm_put(engine);
- return err; }
int intel_engine_pulse(struct intel_engine_cs *engine) {
- struct i915_sched_attr attr = { .priority = I915_PRIORITY_BARRIER }; struct intel_context *ce = engine->kernel_context;
- struct i915_request *rq; int err;
if (!intel_engine_has_preemption(engine)) @@ -215,30 +260,12 @@ int intel_engine_pulse(struct intel_engine_cs *engine) if (!intel_engine_pm_get_if_awake(engine)) return 0;
- if (mutex_lock_interruptible(&ce->timeline->mutex)) {
err = -EINTR;goto out_rpm;
- err = -EINTR;
- if (!mutex_lock_interruptible(&ce->timeline->mutex)) {
err = __intel_engine_pulse(engine);mutex_unlock(&ce->timeline->mutex);
- intel_context_enter(ce);
- rq = __i915_request_create(ce, GFP_NOWAIT | __GFP_NOWARN);
- intel_context_exit(ce);
- if (IS_ERR(rq)) {
err = PTR_ERR(rq);goto out_unlock;- }
- __set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags);
- idle_pulse(engine, rq);
- __i915_request_commit(rq);
- __i915_request_queue(rq, &attr);
- GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER);
- err = 0;
-out_unlock:
- mutex_unlock(&ce->timeline->mutex);
-out_rpm: intel_engine_pm_put(engine); return err; }
Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com
Regards,
Tvrtko
Verify that if a context is active at the time it is closed, that it is either persistent and preemptible (with hangcheck running) or it shall be removed from execution.
Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs") Testcase: igt/gem_ctx_persistence/heartbeat-close Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 48 +++++---------------- 1 file changed, 10 insertions(+), 38 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index a548626fa8bc..4fd38101bb56 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -390,24 +390,6 @@ __context_engines_static(const struct i915_gem_context *ctx) return rcu_dereference_protected(ctx->engines, true); }
-static bool __reset_engine(struct intel_engine_cs *engine) -{ - struct intel_gt *gt = engine->gt; - bool success = false; - - if (!intel_has_reset_engine(gt)) - return false; - - if (!test_and_set_bit(I915_RESET_ENGINE + engine->id, - >->reset.flags)) { - success = intel_engine_reset(engine, NULL) == 0; - clear_and_wake_up_bit(I915_RESET_ENGINE + engine->id, - >->reset.flags); - } - - return success; -} - static void __reset_context(struct i915_gem_context *ctx, struct intel_engine_cs *engine) { @@ -431,12 +413,7 @@ static bool __cancel_engine(struct intel_engine_cs *engine) * kill the banned context, we fallback to doing a local reset * instead. */ - if (IS_ACTIVE(CONFIG_DRM_I915_PREEMPT_TIMEOUT) && - !intel_engine_pulse(engine)) - return true; - - /* If we are unable to send a pulse, try resetting this engine. */ - return __reset_engine(engine); + return intel_engine_pulse(engine) == 0; }
static bool @@ -506,7 +483,7 @@ static struct intel_engine_cs *active_engine(struct intel_context *ce) return engine; }
-static void kill_engines(struct i915_gem_engines *engines) +static void kill_engines(struct i915_gem_engines *engines, bool ban) { struct i915_gem_engines_iter it; struct intel_context *ce; @@ -521,7 +498,7 @@ static void kill_engines(struct i915_gem_engines *engines) for_each_gem_engine(ce, engines, it) { struct intel_engine_cs *engine;
- if (intel_context_set_banned(ce)) + if (ban && intel_context_set_banned(ce)) continue;
/* @@ -534,7 +511,7 @@ static void kill_engines(struct i915_gem_engines *engines) engine = active_engine(ce);
/* First attempt to gracefully cancel the context */ - if (engine && !__cancel_engine(engine)) + if (engine && !__cancel_engine(engine) && ban) /* * If we are unable to send a preemptive pulse to bump * the context from the GPU, we have to resort to a full @@ -544,8 +521,10 @@ static void kill_engines(struct i915_gem_engines *engines) } }
-static void kill_stale_engines(struct i915_gem_context *ctx) +static void kill_context(struct i915_gem_context *ctx) { + bool ban = (!i915_gem_context_is_persistent(ctx) || + !ctx->i915->params.enable_hangcheck); struct i915_gem_engines *pos, *next;
spin_lock_irq(&ctx->stale.lock); @@ -558,7 +537,7 @@ static void kill_stale_engines(struct i915_gem_context *ctx)
spin_unlock_irq(&ctx->stale.lock);
- kill_engines(pos); + kill_engines(pos, ban);
spin_lock_irq(&ctx->stale.lock); GEM_BUG_ON(i915_sw_fence_signaled(&pos->fence)); @@ -570,11 +549,6 @@ static void kill_stale_engines(struct i915_gem_context *ctx) spin_unlock_irq(&ctx->stale.lock); }
-static void kill_context(struct i915_gem_context *ctx) -{ - kill_stale_engines(ctx); -} - static void engines_idle_release(struct i915_gem_context *ctx, struct i915_gem_engines *engines) { @@ -609,7 +583,7 @@ static void engines_idle_release(struct i915_gem_context *ctx,
kill: if (list_empty(&engines->link)) /* raced, already closed */ - kill_engines(engines); + kill_engines(engines, true);
i915_sw_fence_commit(&engines->fence); } @@ -667,9 +641,7 @@ static void context_close(struct i915_gem_context *ctx) * case we opt to forcibly kill off all remaining requests on * context close. */ - if (!i915_gem_context_is_persistent(ctx) || - !ctx->i915->params.enable_hangcheck) - kill_context(ctx); + kill_context(ctx);
i915_gem_context_put(ctx); }
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Chris Wilson -
Tvrtko Ursulin