Chris Wilson <[email protected]> writes: > 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); > + }
My immediate thoughts are on why this and not preallocate pm_qos on init/fini and just add/remove requests on suitable spots? -Mika > + } > + > 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 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
