diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_scheduler.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_scheduler.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index 07d243acf553..7eefccff39bf 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -52,4 +52,22 @@ static inline void i915_priolist_free(struct i915_priolist *p) __i915_priolist_free(p); } +static inline bool i915_scheduler_need_preempt(int prio, int active) +{ + /* + * Allow preemption of low -> normal -> high, but we do + * not allow low priority tasks to preempt other low priority + * tasks under the impression that latency for low priority + * tasks does not matter (as much as background throughput), + * so kiss. + * + * More naturally we would write + * prio >= max(0, last); + * except that we wish to prevent triggering preemption at the same + * priority level: the task that is running should remain running + * to preserve FIFO ordering of dependencies. + */ + return prio > max(I915_PRIORITY_NORMAL - 1, active); +} + #endif /* _I915_SCHEDULER_H_ */ |