[Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
In the idle worker we drop the prolonged GT wakeref used to cover such
essentials as interrupt delivery. (When a CS interrupt arrives, we also
assert that the GT is awake.) However, it turns out that 10ms is not
long enough to be assured that the last CS interrupt has been delivered,
so bump that to 200ms, and move the entirety of that wait to before we
take the struct_mutex to avoid blocking. As this is now a potentially
long wait, restore the earlier behaviour of bailing out early when a new
request arrives.
v2: Break out the repeated check for new requests into its own little
helper to try and improve the self-commentary.
Signed-off-by: Chris Wilson
Cc: Joonas Lahtinen
Cc: Mika Kuoppala
Cc: Imre Deak
Reviewed-by: Mika Kuoppala
---
drivers/gpu/drm/i915/i915_gem.c | 37 ++---
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 026cb52ece0b..bb0e85043e01 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3276,13 +3276,20 @@ i915_gem_retire_work_handler(struct work_struct *work)
}
}
+static inline bool
+new_requests_since_last_retire(const struct drm_i915_private *i915)
+{
+ return (READ_ONCE(i915->gt.active_requests) ||
+ work_pending(&i915->gt.idle_work.work));
+}
+
static void
i915_gem_idle_work_handler(struct work_struct *work)
{
struct drm_i915_private *dev_priv =
container_of(work, typeof(*dev_priv), gt.idle_work.work);
- struct drm_device *dev = &dev_priv->drm;
bool rearm_hangcheck;
+ ktime_t end;
if (!READ_ONCE(dev_priv->gt.awake))
return;
@@ -3291,14 +3298,21 @@ i915_gem_idle_work_handler(struct work_struct *work)
* Wait for last execlists context complete, but bail out in case a
* new request is submitted.
*/
- wait_for(intel_engines_are_idle(dev_priv), 10);
- if (READ_ONCE(dev_priv->gt.active_requests))
- return;
+ end = ktime_add_ms(ktime_get(), 200);
+ do {
+ if (new_requests_since_last_retire(dev_priv))
+ return;
+
+ if (intel_engines_are_idle(dev_priv))
+ break;
+
+ usleep_range(100, 500);
+ } while (ktime_before(ktime_get(), end));
rearm_hangcheck =
cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
- if (!mutex_trylock(&dev->struct_mutex)) {
+ if (!mutex_trylock(&dev_priv->drm.struct_mutex)) {
/* Currently busy, come back later */
mod_delayed_work(dev_priv->wq,
&dev_priv->gt.idle_work,
@@ -3310,13 +3324,14 @@ i915_gem_idle_work_handler(struct work_struct *work)
* New request retired after this work handler started, extend active
* period until next instance of the work.
*/
- if (work_pending(work))
- goto out_unlock;
-
- if (dev_priv->gt.active_requests)
+ if (new_requests_since_last_retire(dev_priv))
goto out_unlock;
- if (wait_for(intel_engines_are_idle(dev_priv), 10))
+ /*
+* We are committed now to parking the engines, make sure there
+* will be no more interrupts arriving later.
+*/
+ if (!intel_engines_are_idle(dev_priv))
DRM_ERROR("Timeout waiting for engines to idle\n");
intel_engines_mark_idle(dev_priv);
@@ -3330,7 +3345,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
gen6_rps_idle(dev_priv);
intel_runtime_pm_put(dev_priv);
out_unlock:
- mutex_unlock(&dev->struct_mutex);
+ mutex_unlock(&dev_priv->drm.struct_mutex);
out_rearm:
if (rearm_hangcheck) {
--
2.15.0.rc1
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Quoting Mika Kuoppala (2017-10-23 12:52:11)
> Chris Wilson writes:
>
> > In the idle worker we drop the prolonged GT wakeref used to cover such
> > essentials as interrupt delivery. (When a CS interrupt arrives, we also
> > assert that the GT is awake.) However, it turns out that 10ms is not
> > long enough to be assured that the last CS interrupt has been delivered,
> > so bump that to 200ms, and move the entirety of that wait to before we
> > take the struct_mutex to avoid blocking. As this is now a potentially
> > long wait, restore the earlier behaviour of bailing out early when a new
> > request arrives.
> >
> > Signed-off-by: Chris Wilson
> > Cc: Joonas Lahtinen
> > Cc: Mika Kuoppala
> > Cc: Imre Deak
> > ---
> > drivers/gpu/drm/i915/i915_gem.c | 31 ---
> > 1 file changed, 20 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c
> > b/drivers/gpu/drm/i915/i915_gem.c
> > index 026cb52ece0b..d3a638613857 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
> > {
> > struct drm_i915_private *dev_priv =
> > container_of(work, typeof(*dev_priv), gt.idle_work.work);
> > - struct drm_device *dev = &dev_priv->drm;
> > bool rearm_hangcheck;
> > + ktime_t end;
> >
> > if (!READ_ONCE(dev_priv->gt.awake))
> > return;
> > @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
> >* Wait for last execlists context complete, but bail out in case a
> >* new request is submitted.
> >*/
> > - wait_for(intel_engines_are_idle(dev_priv), 10);
> > - if (READ_ONCE(dev_priv->gt.active_requests))
> > - return;
> > + end = ktime_add_ms(ktime_get(), 200);
> > + do {
> > + if (READ_ONCE(dev_priv->gt.active_requests) ||
> > + work_pending(work))
> > + return;
> > +
> > + if (intel_engines_are_idle(dev_priv))
> > + break;
> > +
> > + usleep_range(100, 500);
> > + } while (ktime_before(ktime_get(), end));
> >
> > rearm_hangcheck =
> > cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
> >
> > - if (!mutex_trylock(&dev->struct_mutex)) {
> > + if (!mutex_trylock(&dev_priv->drm.struct_mutex)) {
> > /* Currently busy, come back later */
> > mod_delayed_work(dev_priv->wq,
> >&dev_priv->gt.idle_work,
> > @@ -3310,13 +3318,14 @@ i915_gem_idle_work_handler(struct work_struct *work)
> >* New request retired after this work handler started, extend active
> >* period until next instance of the work.
> >*/
> > - if (work_pending(work))
> > + if (dev_priv->gt.active_requests || work_pending(work))
> > goto out_unlock;
> >
>
> In here there might be some value of introducing helper
> for gt_work_pending as you could use it in early bailout and
> in here. You would get one superfluous READ_ONCE by having that inside
> the helper but in idle work it doesnt matter.
>
> I think it would read better too. But as it is in bikesched
> department.
Read better depends on finding the right name.
new_requests_since_last_retire()?
-Chris
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Chris Wilson writes:
> In the idle worker we drop the prolonged GT wakeref used to cover such
> essentials as interrupt delivery. (When a CS interrupt arrives, we also
> assert that the GT is awake.) However, it turns out that 10ms is not
> long enough to be assured that the last CS interrupt has been delivered,
> so bump that to 200ms, and move the entirety of that wait to before we
> take the struct_mutex to avoid blocking. As this is now a potentially
> long wait, restore the earlier behaviour of bailing out early when a new
> request arrives.
>
> Signed-off-by: Chris Wilson
> Cc: Joonas Lahtinen
> Cc: Mika Kuoppala
> Cc: Imre Deak
> ---
> drivers/gpu/drm/i915/i915_gem.c | 31 ---
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 026cb52ece0b..d3a638613857 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
> {
> struct drm_i915_private *dev_priv =
> container_of(work, typeof(*dev_priv), gt.idle_work.work);
> - struct drm_device *dev = &dev_priv->drm;
> bool rearm_hangcheck;
> + ktime_t end;
>
> if (!READ_ONCE(dev_priv->gt.awake))
> return;
> @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
>* Wait for last execlists context complete, but bail out in case a
>* new request is submitted.
>*/
> - wait_for(intel_engines_are_idle(dev_priv), 10);
> - if (READ_ONCE(dev_priv->gt.active_requests))
> - return;
> + end = ktime_add_ms(ktime_get(), 200);
> + do {
> + if (READ_ONCE(dev_priv->gt.active_requests) ||
> + work_pending(work))
> + return;
> +
> + if (intel_engines_are_idle(dev_priv))
> + break;
> +
> + usleep_range(100, 500);
> + } while (ktime_before(ktime_get(), end));
>
> rearm_hangcheck =
> cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
>
> - if (!mutex_trylock(&dev->struct_mutex)) {
> + if (!mutex_trylock(&dev_priv->drm.struct_mutex)) {
> /* Currently busy, come back later */
> mod_delayed_work(dev_priv->wq,
>&dev_priv->gt.idle_work,
> @@ -3310,13 +3318,14 @@ i915_gem_idle_work_handler(struct work_struct *work)
>* New request retired after this work handler started, extend active
>* period until next instance of the work.
>*/
> - if (work_pending(work))
> + if (dev_priv->gt.active_requests || work_pending(work))
> goto out_unlock;
>
In here there might be some value of introducing helper
for gt_work_pending as you could use it in early bailout and
in here. You would get one superfluous READ_ONCE by having that inside
the helper but in idle work it doesnt matter.
I think it would read better too. But as it is in bikesched
department.
Reviewed-by: Mika Kuoppala
> - if (dev_priv->gt.active_requests)
> - goto out_unlock;
> -
> - if (wait_for(intel_engines_are_idle(dev_priv), 10))
> + /*
> + * We are committed now to parking the engines, make sure there
> + * will be no more interrupts arriving later.
> + */
> + if (!intel_engines_are_idle(dev_priv))
> DRM_ERROR("Timeout waiting for engines to idle\n");
>
> intel_engines_mark_idle(dev_priv);
> @@ -3330,7 +3339,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
> gen6_rps_idle(dev_priv);
> intel_runtime_pm_put(dev_priv);
> out_unlock:
> - mutex_unlock(&dev->struct_mutex);
> + mutex_unlock(&dev_priv->drm.struct_mutex);
>
> out_rearm:
> if (rearm_hangcheck) {
> --
> 2.15.0.rc1
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Quoting Mika Kuoppala (2017-10-20 14:23:02)
> Chris Wilson writes:
>
> > Quoting Mika Kuoppala (2017-10-20 14:11:53)
> >> Chris Wilson writes:
> >>
> >> > In the idle worker we drop the prolonged GT wakeref used to cover such
> >> > essentials as interrupt delivery. (When a CS interrupt arrives, we also
> >> > assert that the GT is awake.) However, it turns out that 10ms is not
> >> > long enough to be assured that the last CS interrupt has been delivered,
> >> > so bump that to 200ms, and move the entirety of that wait to before we
> >> > take the struct_mutex to avoid blocking. As this is now a potentially
> >> > long wait, restore the earlier behaviour of bailing out early when a new
> >> > request arrives.
> >> >
> >> > Signed-off-by: Chris Wilson
> >> > Cc: Joonas Lahtinen
> >> > Cc: Mika Kuoppala
> >> > Cc: Imre Deak
> >> > ---
> >> > drivers/gpu/drm/i915/i915_gem.c | 31 ---
> >> > 1 file changed, 20 insertions(+), 11 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/i915_gem.c
> >> > b/drivers/gpu/drm/i915/i915_gem.c
> >> > index 026cb52ece0b..d3a638613857 100644
> >> > --- a/drivers/gpu/drm/i915/i915_gem.c
> >> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> >> > @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct
> >> > *work)
> >> > {
> >> > struct drm_i915_private *dev_priv =
> >> > container_of(work, typeof(*dev_priv), gt.idle_work.work);
> >> > - struct drm_device *dev = &dev_priv->drm;
> >> > bool rearm_hangcheck;
> >> > + ktime_t end;
> >> >
> >> > if (!READ_ONCE(dev_priv->gt.awake))
> >> > return;
> >> > @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct
> >> > *work)
> >> >* Wait for last execlists context complete, but bail out in case a
> >> >* new request is submitted.
> >> >*/
> >> > - wait_for(intel_engines_are_idle(dev_priv), 10);
> >> > - if (READ_ONCE(dev_priv->gt.active_requests))
> >> > - return;
> >> > + end = ktime_add_ms(ktime_get(), 200);
> >> > + do {
> >> > + if (READ_ONCE(dev_priv->gt.active_requests) ||
> >> > + work_pending(work))
> >> > + return;
> >> > +
> >> > + if (intel_engines_are_idle(dev_priv))
> >> > + break;
> >> > +
> >> > + usleep_range(100, 500);
> >> > + } while (ktime_before(ktime_get(), end));
> >> >
> >>
> >> Why can't we just wait_for(intel_engines_are_idle(dev_priv, 200)) ?
> >
> > That return. We don't really want to block the ordered wq for 200ms when
> > we already know we won't make progress. (Whilst we are running nothing
> > else that wants to use dev_priv->wq can.)
>
> Ok, that makes sense but why don't we have own workqueue for the
> idleworker?
We have a wq for those lowfreq work that need struct_mutex. We don't
really need it, it just helps to have a named wq when staring at a stuck
machine. One wq per struct work_struct would seem to be overkill ;)
-Chris
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Chris Wilson writes:
> Quoting Mika Kuoppala (2017-10-20 14:11:53)
>> Chris Wilson writes:
>>
>> > In the idle worker we drop the prolonged GT wakeref used to cover such
>> > essentials as interrupt delivery. (When a CS interrupt arrives, we also
>> > assert that the GT is awake.) However, it turns out that 10ms is not
>> > long enough to be assured that the last CS interrupt has been delivered,
>> > so bump that to 200ms, and move the entirety of that wait to before we
>> > take the struct_mutex to avoid blocking. As this is now a potentially
>> > long wait, restore the earlier behaviour of bailing out early when a new
>> > request arrives.
>> >
>> > Signed-off-by: Chris Wilson
>> > Cc: Joonas Lahtinen
>> > Cc: Mika Kuoppala
>> > Cc: Imre Deak
>> > ---
>> > drivers/gpu/drm/i915/i915_gem.c | 31 ---
>> > 1 file changed, 20 insertions(+), 11 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/i915_gem.c
>> > b/drivers/gpu/drm/i915/i915_gem.c
>> > index 026cb52ece0b..d3a638613857 100644
>> > --- a/drivers/gpu/drm/i915/i915_gem.c
>> > +++ b/drivers/gpu/drm/i915/i915_gem.c
>> > @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
>> > {
>> > struct drm_i915_private *dev_priv =
>> > container_of(work, typeof(*dev_priv), gt.idle_work.work);
>> > - struct drm_device *dev = &dev_priv->drm;
>> > bool rearm_hangcheck;
>> > + ktime_t end;
>> >
>> > if (!READ_ONCE(dev_priv->gt.awake))
>> > return;
>> > @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct
>> > *work)
>> >* Wait for last execlists context complete, but bail out in case a
>> >* new request is submitted.
>> >*/
>> > - wait_for(intel_engines_are_idle(dev_priv), 10);
>> > - if (READ_ONCE(dev_priv->gt.active_requests))
>> > - return;
>> > + end = ktime_add_ms(ktime_get(), 200);
>> > + do {
>> > + if (READ_ONCE(dev_priv->gt.active_requests) ||
>> > + work_pending(work))
>> > + return;
>> > +
>> > + if (intel_engines_are_idle(dev_priv))
>> > + break;
>> > +
>> > + usleep_range(100, 500);
>> > + } while (ktime_before(ktime_get(), end));
>> >
>>
>> Why can't we just wait_for(intel_engines_are_idle(dev_priv, 200)) ?
>
> That return. We don't really want to block the ordered wq for 200ms when
> we already know we won't make progress. (Whilst we are running nothing
> else that wants to use dev_priv->wq can.)
Ok, that makes sense but why don't we have own workqueue for the
idleworker?
-Mika
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Quoting Mika Kuoppala (2017-10-20 14:11:53)
> Chris Wilson writes:
>
> > In the idle worker we drop the prolonged GT wakeref used to cover such
> > essentials as interrupt delivery. (When a CS interrupt arrives, we also
> > assert that the GT is awake.) However, it turns out that 10ms is not
> > long enough to be assured that the last CS interrupt has been delivered,
> > so bump that to 200ms, and move the entirety of that wait to before we
> > take the struct_mutex to avoid blocking. As this is now a potentially
> > long wait, restore the earlier behaviour of bailing out early when a new
> > request arrives.
> >
> > Signed-off-by: Chris Wilson
> > Cc: Joonas Lahtinen
> > Cc: Mika Kuoppala
> > Cc: Imre Deak
> > ---
> > drivers/gpu/drm/i915/i915_gem.c | 31 ---
> > 1 file changed, 20 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c
> > b/drivers/gpu/drm/i915/i915_gem.c
> > index 026cb52ece0b..d3a638613857 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
> > {
> > struct drm_i915_private *dev_priv =
> > container_of(work, typeof(*dev_priv), gt.idle_work.work);
> > - struct drm_device *dev = &dev_priv->drm;
> > bool rearm_hangcheck;
> > + ktime_t end;
> >
> > if (!READ_ONCE(dev_priv->gt.awake))
> > return;
> > @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
> >* Wait for last execlists context complete, but bail out in case a
> >* new request is submitted.
> >*/
> > - wait_for(intel_engines_are_idle(dev_priv), 10);
> > - if (READ_ONCE(dev_priv->gt.active_requests))
> > - return;
> > + end = ktime_add_ms(ktime_get(), 200);
> > + do {
> > + if (READ_ONCE(dev_priv->gt.active_requests) ||
> > + work_pending(work))
> > + return;
> > +
> > + if (intel_engines_are_idle(dev_priv))
> > + break;
> > +
> > + usleep_range(100, 500);
> > + } while (ktime_before(ktime_get(), end));
> >
>
> Why can't we just wait_for(intel_engines_are_idle(dev_priv, 200)) ?
That return. We don't really want to block the ordered wq for 200ms when
we already know we won't make progress. (Whilst we are running nothing
else that wants to use dev_priv->wq can.)
-Chris
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Re: [Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
Chris Wilson writes:
> In the idle worker we drop the prolonged GT wakeref used to cover such
> essentials as interrupt delivery. (When a CS interrupt arrives, we also
> assert that the GT is awake.) However, it turns out that 10ms is not
> long enough to be assured that the last CS interrupt has been delivered,
> so bump that to 200ms, and move the entirety of that wait to before we
> take the struct_mutex to avoid blocking. As this is now a potentially
> long wait, restore the earlier behaviour of bailing out early when a new
> request arrives.
>
> Signed-off-by: Chris Wilson
> Cc: Joonas Lahtinen
> Cc: Mika Kuoppala
> Cc: Imre Deak
> ---
> drivers/gpu/drm/i915/i915_gem.c | 31 ---
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 026cb52ece0b..d3a638613857 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
> {
> struct drm_i915_private *dev_priv =
> container_of(work, typeof(*dev_priv), gt.idle_work.work);
> - struct drm_device *dev = &dev_priv->drm;
> bool rearm_hangcheck;
> + ktime_t end;
>
> if (!READ_ONCE(dev_priv->gt.awake))
> return;
> @@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
>* Wait for last execlists context complete, but bail out in case a
>* new request is submitted.
>*/
> - wait_for(intel_engines_are_idle(dev_priv), 10);
> - if (READ_ONCE(dev_priv->gt.active_requests))
> - return;
> + end = ktime_add_ms(ktime_get(), 200);
> + do {
> + if (READ_ONCE(dev_priv->gt.active_requests) ||
> + work_pending(work))
> + return;
> +
> + if (intel_engines_are_idle(dev_priv))
> + break;
> +
> + usleep_range(100, 500);
> + } while (ktime_before(ktime_get(), end));
>
Why can't we just wait_for(intel_engines_are_idle(dev_priv, 200)) ?
-Mika
> rearm_hangcheck =
> cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
>
> - if (!mutex_trylock(&dev->struct_mutex)) {
> + if (!mutex_trylock(&dev_priv->drm.struct_mutex)) {
> /* Currently busy, come back later */
> mod_delayed_work(dev_priv->wq,
>&dev_priv->gt.idle_work,
> @@ -3310,13 +3318,14 @@ i915_gem_idle_work_handler(struct work_struct *work)
>* New request retired after this work handler started, extend active
>* period until next instance of the work.
>*/
> - if (work_pending(work))
> + if (dev_priv->gt.active_requests || work_pending(work))
> goto out_unlock;
>
> - if (dev_priv->gt.active_requests)
> - goto out_unlock;
> -
> - if (wait_for(intel_engines_are_idle(dev_priv), 10))
> + /*
> + * We are committed now to parking the engines, make sure there
> + * will be no more interrupts arriving later.
> + */
> + if (!intel_engines_are_idle(dev_priv))
> DRM_ERROR("Timeout waiting for engines to idle\n");
>
> intel_engines_mark_idle(dev_priv);
> @@ -3330,7 +3339,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
> gen6_rps_idle(dev_priv);
> intel_runtime_pm_put(dev_priv);
> out_unlock:
> - mutex_unlock(&dev->struct_mutex);
> + mutex_unlock(&dev_priv->drm.struct_mutex);
>
> out_rearm:
> if (rearm_hangcheck) {
> --
> 2.15.0.rc1
___
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[Intel-gfx] [PATCH 1/2] drm/i915: Bump wait-times for the final CS interrupt before parking
In the idle worker we drop the prolonged GT wakeref used to cover such
essentials as interrupt delivery. (When a CS interrupt arrives, we also
assert that the GT is awake.) However, it turns out that 10ms is not
long enough to be assured that the last CS interrupt has been delivered,
so bump that to 200ms, and move the entirety of that wait to before we
take the struct_mutex to avoid blocking. As this is now a potentially
long wait, restore the earlier behaviour of bailing out early when a new
request arrives.
Signed-off-by: Chris Wilson
Cc: Joonas Lahtinen
Cc: Mika Kuoppala
Cc: Imre Deak
---
drivers/gpu/drm/i915/i915_gem.c | 31 ---
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 026cb52ece0b..d3a638613857 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3281,8 +3281,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
{
struct drm_i915_private *dev_priv =
container_of(work, typeof(*dev_priv), gt.idle_work.work);
- struct drm_device *dev = &dev_priv->drm;
bool rearm_hangcheck;
+ ktime_t end;
if (!READ_ONCE(dev_priv->gt.awake))
return;
@@ -3291,14 +3291,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
* Wait for last execlists context complete, but bail out in case a
* new request is submitted.
*/
- wait_for(intel_engines_are_idle(dev_priv), 10);
- if (READ_ONCE(dev_priv->gt.active_requests))
- return;
+ end = ktime_add_ms(ktime_get(), 200);
+ do {
+ if (READ_ONCE(dev_priv->gt.active_requests) ||
+ work_pending(work))
+ return;
+
+ if (intel_engines_are_idle(dev_priv))
+ break;
+
+ usleep_range(100, 500);
+ } while (ktime_before(ktime_get(), end));
rearm_hangcheck =
cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
- if (!mutex_trylock(&dev->struct_mutex)) {
+ if (!mutex_trylock(&dev_priv->drm.struct_mutex)) {
/* Currently busy, come back later */
mod_delayed_work(dev_priv->wq,
&dev_priv->gt.idle_work,
@@ -3310,13 +3318,14 @@ i915_gem_idle_work_handler(struct work_struct *work)
* New request retired after this work handler started, extend active
* period until next instance of the work.
*/
- if (work_pending(work))
+ if (dev_priv->gt.active_requests || work_pending(work))
goto out_unlock;
- if (dev_priv->gt.active_requests)
- goto out_unlock;
-
- if (wait_for(intel_engines_are_idle(dev_priv), 10))
+ /*
+* We are committed now to parking the engines, make sure there
+* will be no more interrupts arriving later.
+*/
+ if (!intel_engines_are_idle(dev_priv))
DRM_ERROR("Timeout waiting for engines to idle\n");
intel_engines_mark_idle(dev_priv);
@@ -3330,7 +3339,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
gen6_rps_idle(dev_priv);
intel_runtime_pm_put(dev_priv);
out_unlock:
- mutex_unlock(&dev->struct_mutex);
+ mutex_unlock(&dev_priv->drm.struct_mutex);
out_rearm:
if (rearm_hangcheck) {
--
2.15.0.rc1
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