If we are waiting for the currently executing request, we have a good idea that it will be completed in the very near future and so want to cap the CPU_DMA_LATENCY to ensure that we wake up the client quickly.
v2: Not allowed to block in kmalloc after setting TASK_INTERRUPTIBLE. v3: Avoid the blocking notifier as well for TASK_INTERRUPTIBLE Testcase: igt/gem_sync/store-default Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Eero Tamminen <[email protected]> Cc: Francisco Jerez <[email protected]> --- drivers/gpu/drm/i915/i915_request.c | 38 +++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 5c2c93cbab12..7c7746ef0d1b 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1258,6 +1258,28 @@ static bool __i915_wait_request_check_and_reset(struct i915_request *request) return true; } +struct pm_qos { + struct pm_qos_request req; + struct work_struct add, del; +}; + +static void pm_qos_add(struct work_struct *work) +{ + struct pm_qos *pm_qos = container_of(work, typeof(*pm_qos), add); + + pm_qos_add_request(&pm_qos->req, PM_QOS_CPU_DMA_LATENCY, 50); +} + +static void pm_qos_del(struct work_struct *work) +{ + struct pm_qos *pm_qos = container_of(work, typeof(*pm_qos), del); + + if (!cancel_work_sync(&pm_qos->add)) + pm_qos_remove_request(&pm_qos->req); + + kfree(pm_qos); +} + /** * i915_request_wait - wait until execution of request has finished * @rq: the request to wait upon @@ -1286,6 +1308,7 @@ long i915_request_wait(struct i915_request *rq, wait_queue_head_t *errq = &rq->i915->gpu_error.wait_queue; DEFINE_WAIT_FUNC(reset, default_wake_function); DEFINE_WAIT_FUNC(exec, default_wake_function); + struct pm_qos *pm_qos = NULL; struct intel_wait wait; might_sleep(); @@ -1363,6 +1386,19 @@ long i915_request_wait(struct i915_request *rq, break; } + if (!pm_qos && + i915_seqno_passed(intel_engine_get_seqno(rq->engine), + wait.seqno - 1)) { + pm_qos = kzalloc(sizeof(*pm_qos), + GFP_NOWAIT | __GFP_NOWARN); + if (pm_qos) { + INIT_WORK(&pm_qos->add, pm_qos_add); + INIT_WORK(&pm_qos->del, pm_qos_del); + schedule_work_on(smp_processor_id(), + &pm_qos->add); + } + } + timeout = io_schedule_timeout(timeout); if (intel_wait_complete(&wait) && @@ -1412,6 +1448,8 @@ long i915_request_wait(struct i915_request *rq, if (flags & I915_WAIT_LOCKED) remove_wait_queue(errq, &reset); remove_wait_queue(&rq->execute, &exec); + if (pm_qos) + schedule_work(&pm_qos->del); trace_i915_request_wait_end(rq); return timeout; -- 2.18.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
