[Intel-gfx] [PATCH v2 2/3] drm/i915: add a dedicated workqueue inside drm_i915_private
Coelho, Luciano
luciano.coelho at intel.com
Wed May 24 12:25:35 UTC 2023
On Wed, 2023-05-24 at 12:00 +0100, Tvrtko Ursulin wrote:
> On 24/05/2023 10:05, Luca Coelho wrote:
> > In order to avoid flush_scheduled_work() usage, add a dedicated
> > workqueue in the drm_i915_private structure. In this way, we don't
> > need to use the system queue anymore.
> >
> > This change is mostly mechanical and based on Tetsuo's original
> > patch[1].
> >
> > Link: https://patchwork.freedesktop.org/series/114608/ [1]
> > Cc: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 5 ++--
> > .../drm/i915/display/intel_display_driver.c | 2 +-
> > drivers/gpu/drm/i915/display/intel_dmc.c | 2 +-
> > drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
> > .../drm/i915/display/intel_dp_link_training.c | 3 ++-
> > drivers/gpu/drm/i915/display/intel_drrs.c | 4 +++-
> > drivers/gpu/drm/i915/display/intel_fbc.c | 2 +-
> > drivers/gpu/drm/i915/display/intel_fbdev.c | 3 ++-
> > drivers/gpu/drm/i915/display/intel_hdcp.c | 23 +++++++++++--------
> > drivers/gpu/drm/i915/display/intel_hotplug.c | 18 ++++++++++-----
> > drivers/gpu/drm/i915/display/intel_opregion.c | 3 ++-
> > drivers/gpu/drm/i915/display/intel_pps.c | 4 +++-
> > drivers/gpu/drm/i915/display/intel_psr.c | 8 ++++---
> > .../drm/i915/gt/intel_execlists_submission.c | 5 ++--
> > .../gpu/drm/i915/gt/intel_gt_buffer_pool.c | 10 ++++----
> > drivers/gpu/drm/i915/gt/intel_gt_irq.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_gt_requests.c | 10 ++++----
> > drivers/gpu/drm/i915/gt/intel_reset.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_rps.c | 20 ++++++++--------
> > drivers/gpu/drm/i915/gt/selftest_engine_cs.c | 2 +-
> > drivers/gpu/drm/i915/i915_driver.c | 11 +++++++++
> > drivers/gpu/drm/i915/i915_drv.h | 9 +++++++-
> > drivers/gpu/drm/i915/i915_request.c | 2 +-
> > drivers/gpu/drm/i915/intel_wakeref.c | 2 +-
> > 24 files changed, 99 insertions(+), 55 deletions(-)
>
> I'll take a look at the gt/ parts only since display experts need to
> okay the point Daniel raise anyway.
Thanks!
> 8<
> > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > index 750326434677..2ebd937f3b4c 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> > @@ -2327,6 +2327,7 @@ static u32 active_ccid(struct intel_engine_cs *engine)
> >
> > static void execlists_capture(struct intel_engine_cs *engine)
> > {
> > + struct drm_i915_private *i915 = engine->i915;
> > struct execlists_capture *cap;
> >
> > if (!IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR))
> > @@ -2375,7 +2376,7 @@ static void execlists_capture(struct intel_engine_cs *engine)
> > goto err_rq;
> >
> > INIT_WORK(&cap->work, execlists_capture_work);
> > - schedule_work(&cap->work);
> > + queue_work(i915->unordered_wq, &cap->work);
> > return;
> >
> > err_rq:
> > @@ -3680,7 +3681,7 @@ static void virtual_context_destroy(struct kref *kref)
> > * lock, we can delegate the free of the engine to an RCU worker.
> > */
> > INIT_RCU_WORK(&ve->rcu, rcu_virtual_context_destroy);
> > - queue_rcu_work(system_wq, &ve->rcu);
> > + queue_rcu_work(ve->context.engine->i915->unordered_wq, &ve->rcu);
> > }
> >
> > static void virtual_engine_initial_hint(struct virtual_engine *ve)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
> > index cadfd85785b1..86b5a9ba323d 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c
> > @@ -88,10 +88,11 @@ static void pool_free_work(struct work_struct *wrk)
> > {
> > struct intel_gt_buffer_pool *pool =
> > container_of(wrk, typeof(*pool), work.work);
> > + struct intel_gt *gt = container_of(pool, struct intel_gt, buffer_pool);
>
> Okay. Or alternatively, pool = >->buffer_pool, might read simpler...
Sorry, I don't follow. wrk is inside intel_gt_buffer_pool, so we can
derive pool from work. And then we know that pool is inside intel_gt,
so we derive gt from that. How would I get gt first and derive pool
from that?
> >
> > if (pool_free_older_than(pool, HZ))
> > - schedule_delayed_work(&pool->work,
> > - round_jiffies_up_relative(HZ));
> > + queue_delayed_work(gt->i915->unordered_wq, &pool->work,
> > + round_jiffies_up_relative(HZ));
> > }
> >
> > static void pool_retire(struct i915_active *ref)
> > @@ -99,6 +100,7 @@ static void pool_retire(struct i915_active *ref)
> > struct intel_gt_buffer_pool_node *node =
> > container_of(ref, typeof(*node), active);
> > struct intel_gt_buffer_pool *pool = node->pool;
> > + struct intel_gt *gt = container_of(pool, struct intel_gt, buffer_pool);
>
> ... although I am beginning to wonder if intel_gt_buffer_pool shouldn't
> just gain a gt backpointer? That would decouple things more instead of
> tying the implementation with intel_gt implicitly. Not a strong
> direction though.
>
> > struct list_head *list = bucket_for_size(pool, node->obj->base.size);
> > unsigned long flags;
> >
> > @@ -116,8 +118,8 @@ static void pool_retire(struct i915_active *ref)
> > WRITE_ONCE(node->age, jiffies ?: 1); /* 0 reserved for active nodes */
> > spin_unlock_irqrestore(&pool->lock, flags);
> >
> > - schedule_delayed_work(&pool->work,
> > - round_jiffies_up_relative(HZ));
> > + queue_delayed_work(gt->i915->unordered_wq, &pool->work,
> > + round_jiffies_up_relative(HZ));
> > }
> >
> > void intel_gt_buffer_pool_mark_used(struct intel_gt_buffer_pool_node *node)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > index 8f888d36f16d..62fd00c9e519 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > @@ -376,7 +376,7 @@ static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir)
> > if (iir & GT_RENDER_L3_PARITY_ERROR_INTERRUPT)
> > gt->i915->l3_parity.which_slice |= 1 << 0;
> >
> > - schedule_work(>->i915->l3_parity.error_work);
> > + queue_work(gt->i915->unordered_wq, >->i915->l3_parity.error_work);
> > }
> >
> > void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> > index 1dfd01668c79..d1a382dfaa1d 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> > @@ -116,7 +116,7 @@ void intel_engine_add_retire(struct intel_engine_cs *engine,
> > GEM_BUG_ON(intel_engine_is_virtual(engine));
> >
> > if (add_retire(engine, tl))
> > - schedule_work(&engine->retire_work);
> > + queue_work(engine->i915->unordered_wq, &engine->retire_work);
> > }
> >
> > void intel_engine_init_retire(struct intel_engine_cs *engine)
> > @@ -207,8 +207,8 @@ static void retire_work_handler(struct work_struct *work)
> > struct intel_gt *gt =
> > container_of(work, typeof(*gt), requests.retire_work.work);
> >
> > - schedule_delayed_work(>->requests.retire_work,
> > - round_jiffies_up_relative(HZ));
> > + queue_delayed_work(gt->i915->unordered_wq, >->requests.retire_work,
> > + round_jiffies_up_relative(HZ));
> > intel_gt_retire_requests(gt);
> > }
> >
> > @@ -224,8 +224,8 @@ void intel_gt_park_requests(struct intel_gt *gt)
> >
> > void intel_gt_unpark_requests(struct intel_gt *gt)
> > {
> > - schedule_delayed_work(>->requests.retire_work,
> > - round_jiffies_up_relative(HZ));
> > + queue_delayed_work(gt->i915->unordered_wq, >->requests.retire_work,
> > + round_jiffies_up_relative(HZ));
> > }
> >
> > void intel_gt_fini_requests(struct intel_gt *gt)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
> > index 195ff72d7a14..e2152f75ba2e 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> > @@ -1625,7 +1625,7 @@ void __intel_init_wedge(struct intel_wedge_me *w,
> > w->name = name;
> >
> > INIT_DELAYED_WORK_ONSTACK(&w->work, intel_wedge_me);
> > - schedule_delayed_work(&w->work, timeout);
> > + queue_delayed_work(gt->i915->unordered_wq, &w->work, timeout);
> > }
> >
> > void __intel_fini_wedge(struct intel_wedge_me *w)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
> > index e68a99205599..e92e626d4994 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> > @@ -73,13 +73,14 @@ static void set(struct intel_uncore *uncore, i915_reg_t reg, u32 val)
> > static void rps_timer(struct timer_list *t)
> > {
> > struct intel_rps *rps = from_timer(rps, t, timer);
> > + struct intel_gt *gt = rps_to_gt(rps);
> > struct intel_engine_cs *engine;
> > ktime_t dt, last, timestamp;
> > enum intel_engine_id id;
> > s64 max_busy[3] = {};
> >
> > timestamp = 0;
> > - for_each_engine(engine, rps_to_gt(rps), id) {
> > + for_each_engine(engine, gt, id) {
> > s64 busy;
> > int i;
> >
> > @@ -123,7 +124,7 @@ static void rps_timer(struct timer_list *t)
> >
> > busy += div_u64(max_busy[i], 1 << i);
> > }
> > - GT_TRACE(rps_to_gt(rps),
> > + GT_TRACE(gt,
> > "busy:%lld [%d%%], max:[%lld, %lld, %lld], interval:%d\n",
> > busy, (int)div64_u64(100 * busy, dt),
> > max_busy[0], max_busy[1], max_busy[2],
> > @@ -133,12 +134,12 @@ static void rps_timer(struct timer_list *t)
> > rps->cur_freq < rps->max_freq_softlimit) {
> > rps->pm_iir |= GEN6_PM_RP_UP_THRESHOLD;
> > rps->pm_interval = 1;
> > - schedule_work(&rps->work);
> > + queue_work(gt->i915->unordered_wq, &rps->work);
> > } else if (100 * busy < rps->power.down_threshold * dt &&
> > rps->cur_freq > rps->min_freq_softlimit) {
> > rps->pm_iir |= GEN6_PM_RP_DOWN_THRESHOLD;
> > rps->pm_interval = 1;
> > - schedule_work(&rps->work);
> > + queue_work(gt->i915->unordered_wq, &rps->work);
> > } else {
> > rps->last_adj = 0;
> > }
> > @@ -973,7 +974,7 @@ static int rps_set_boost_freq(struct intel_rps *rps, u32 val)
> > }
> > mutex_unlock(&rps->lock);
> > if (boost)
> > - schedule_work(&rps->work);
> > + queue_work(rps_to_gt(rps)->i915->unordered_wq, &rps->work);
> >
> > return 0;
> > }
> > @@ -1025,7 +1026,8 @@ void intel_rps_boost(struct i915_request *rq)
> > if (!atomic_fetch_inc(&slpc->num_waiters)) {
> > GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n",
> > rq->fence.context, rq->fence.seqno);
> > - schedule_work(&slpc->boost_work);
> > + queue_work(rps_to_gt(rps)->i915->unordered_wq,
> > + &slpc->boost_work);
> > }
> >
> > return;
> > @@ -1041,7 +1043,7 @@ void intel_rps_boost(struct i915_request *rq)
> > rq->fence.context, rq->fence.seqno);
> >
> > if (READ_ONCE(rps->cur_freq) < rps->boost_freq)
> > - schedule_work(&rps->work);
> > + queue_work(rps_to_gt(rps)->i915->unordered_wq, &rps->work);
> >
> > WRITE_ONCE(rps->boosts, rps->boosts + 1); /* debug only */
> > }
> > @@ -1900,7 +1902,7 @@ void gen11_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
> > gen6_gt_pm_mask_irq(gt, events);
> >
> > rps->pm_iir |= events;
> > - schedule_work(&rps->work);
> > + queue_work(gt->i915->unordered_wq, &rps->work);
> > }
> >
> > void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
> > @@ -1917,7 +1919,7 @@ void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
> > gen6_gt_pm_mask_irq(gt, events);
> > rps->pm_iir |= events;
> >
> > - schedule_work(&rps->work);
> > + queue_work(gt->i915->unordered_wq, &rps->work);
> > spin_unlock(gt->irq_lock);
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
> > index 542ce6d2de19..78cdfc6f315f 100644
> > --- a/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/gt/selftest_engine_cs.c
> > @@ -27,7 +27,7 @@ static void perf_begin(struct intel_gt *gt)
> >
> > /* Boost gpufreq to max [waitboost] and keep it fixed */
> > atomic_inc(>->rps.num_waiters);
> > - schedule_work(>->rps.work);
> > + queue_work(gt->i915->unordered_wq, >->rps.work);
> > flush_work(>->rps.work);
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> > index 522733a89946..88808aa85b26 100644
> > --- a/drivers/gpu/drm/i915/i915_driver.c
> > +++ b/drivers/gpu/drm/i915/i915_driver.c
> > @@ -132,8 +132,18 @@ static int i915_workqueues_init(struct drm_i915_private *dev_priv)
> > if (dev_priv->display.hotplug.dp_wq == NULL)
> > goto out_free_wq;
> >
> > + /*
> > + * The unordered i915 workqueue should be used for all work
> > + * scheduling that do not require running in order.
> > + */
>
> Ha-ha. Nice cop out. ;) But okay, now that we have two we don't know
> when to use each that well so not fair on you to figure it out.
:D
To be honest, I looked at all the existing users and described pretty
much what is happening. As far as I could tell, someone started using
the system queue a long time ago and, in lack of better alternatives,
everyone else who needed a work followed that. So the new queue is
indeed a catch all for non-ordered queues at the moment (in pretty much
the same way as the system queue was before)...
Additionally, I don't know all the current users well, since they are
everywhere, and I don't think there has been a specific rule when to
use the system queue before.
I'm totally open for better descriptions. :)
> > + dev_priv->unordered_wq = alloc_workqueue("i915-unordered", 0, 0);
> > + if (dev_priv->unordered_wq == NULL)
> > + goto out_free_dp_wq;
> > +
> > return 0;
> >
> > +out_free_dp_wq:
> > + destroy_workqueue(dev_priv->unordered_wq);
>
> Wrong wq.
Ouch. Good catch.
> > out_free_wq:
> > destroy_workqueue(dev_priv->wq);
> > out_err:
> > @@ -144,6 +154,7 @@ static int i915_workqueues_init(struct drm_i915_private *dev_priv)
> >
> > static void i915_workqueues_cleanup(struct drm_i915_private *dev_priv)
> > {
> > + destroy_workqueue(dev_priv->unordered_wq);
> > destroy_workqueue(dev_priv->display.hotplug.dp_wq);
> > destroy_workqueue(dev_priv->wq);
> > }
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 14c5338c96a6..8f2665e8afb5 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -259,6 +259,14 @@ struct drm_i915_private {
> > */
> > struct workqueue_struct *wq;
> >
> > + /**
> > + * unordered_wq - internal workqueue for unordered work
> > + *
> > + * This workqueue should be used for all unordered work
> > + * scheduling within i915.
>
> Proably add something like ", which used to be scheduled on the
> system_wq before moving to a driver instance due deprecation of
> flush_scheduled_work()."
I did start writing something like that, but then I thought that, in
the code, writing about the history of the implementation doesn't add
much. We have the git log for that. But, obviously, I can add that if
you want.
> That way we leave some note to the reader.
>
> > + */
> > + struct workqueue_struct *unordered_wq;
> > +
> > /* pm private clock gating functions */
> > const struct drm_i915_clock_gating_funcs *clock_gating_funcs;
> >
> > @@ -930,5 +938,4 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
> >
> > #define HAS_LMEMBAR_SMEM_STOLEN(i915) (!HAS_LMEM(i915) && \
> > GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
> > -
>
> Tidy if you can please.
Oops!
> > #endif
> > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> > index 630a732aaecc..894068bb37b6 100644
> > --- a/drivers/gpu/drm/i915/i915_request.c
> > +++ b/drivers/gpu/drm/i915/i915_request.c
> > @@ -290,7 +290,7 @@ static enum hrtimer_restart __rq_watchdog_expired(struct hrtimer *hrtimer)
> >
> > if (!i915_request_completed(rq)) {
> > if (llist_add(&rq->watchdog.link, >->watchdog.list))
> > - schedule_work(>->watchdog.work);
> > + queue_work(gt->i915->unordered_wq, >->watchdog.work);
> > } else {
> > i915_request_put(rq);
> > }
> > diff --git a/drivers/gpu/drm/i915/intel_wakeref.c b/drivers/gpu/drm/i915/intel_wakeref.c
> > index 40aafe676017..497ea21a347e 100644
> > --- a/drivers/gpu/drm/i915/intel_wakeref.c
> > +++ b/drivers/gpu/drm/i915/intel_wakeref.c
> > @@ -75,7 +75,7 @@ void __intel_wakeref_put_last(struct intel_wakeref *wf, unsigned long flags)
> >
> > /* Assume we are not in process context and so cannot sleep. */
> > if (flags & INTEL_WAKEREF_PUT_ASYNC || !mutex_trylock(&wf->mutex)) {
> > - mod_delayed_work(system_wq, &wf->work,
> > + mod_delayed_work(wf->i915->wq, &wf->work,
> > FIELD_GET(INTEL_WAKEREF_PUT_DELAY, flags));
> > return;
> > }
>
> Pending the one or two details the non-display parts look good to me.
Great, thanks! I'll send a new version addressing your comments and
wait for display parts review.
--
Cheers,
Luca.
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