diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_breadcrumbs.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_breadcrumbs.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c index a7740696114d..58c624f982d9 100644 --- a/drivers/gpu/drm/i915/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c @@ -27,6 +27,12 @@ #include "i915_drv.h" +#ifdef CONFIG_SMP +#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL && !(tsk)->on_cpu) +#else +#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL) +#endif + static unsigned int __intel_breadcrumbs_wakeup(struct intel_breadcrumbs *b) { struct intel_wait *wait; @@ -36,8 +42,20 @@ static unsigned int __intel_breadcrumbs_wakeup(struct intel_breadcrumbs *b) wait = b->irq_wait; if (wait) { + /* + * N.B. Since task_asleep() and ttwu are not atomic, the + * waiter may actually go to sleep after the check, causing + * us to suppress a valid wakeup. We prefer to reduce the + * number of false positive missed_breadcrumb() warnings + * at the expense of a few false negatives, as it it easy + * to trigger a false positive under heavy load. Enough + * signal should remain from genuine missed_breadcrumb() + * for us to detect in CI. + */ + bool was_asleep = task_asleep(wait->tsk); + result = ENGINE_WAKEUP_WAITER; - if (wake_up_process(wait->tsk)) + if (wake_up_process(wait->tsk) && was_asleep) result |= ENGINE_WAKEUP_ASLEEP; } @@ -77,8 +95,8 @@ static noinline void missed_breadcrumb(struct intel_engine_cs *engine) static void intel_breadcrumbs_hangcheck(struct timer_list *t) { - struct intel_engine_cs *engine = from_timer(engine, t, - breadcrumbs.hangcheck); + struct intel_engine_cs *engine = + from_timer(engine, t, breadcrumbs.hangcheck); struct intel_breadcrumbs *b = &engine->breadcrumbs; if (!b->irq_armed) @@ -104,7 +122,7 @@ static void intel_breadcrumbs_hangcheck(struct timer_list *t) */ if (intel_engine_wakeup(engine) & ENGINE_WAKEUP_ASLEEP) { missed_breadcrumb(engine); - mod_timer(&engine->breadcrumbs.fake_irq, jiffies + 1); + mod_timer(&b->fake_irq, jiffies + 1); } else { mod_timer(&b->hangcheck, wait_timeout()); } |