Messages in this thread | | | Date | Fri, 31 Mar 2023 15:51:51 +0100 | Subject | Re: [PATCH v2] drm/i915/gt: Hold a wakeref for the active VM | From | Tvrtko Ursulin <> |
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On 31/03/2023 15:16, Andrzej Hajda wrote: > From: Chris Wilson <chris@chris-wilson.co.uk> > > There may be a disconnect between the GT used by the engine and the GT > used for the VM, requiring us to hold a wakeref on both while the GPU is > active with this request. > > v2: added explanation to __queue_and_release_pm > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > [ahajda: removed not-yet-upstremed wakeref tracking bits] > Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> > --- > Changes in v2: > - Link to v1: https://lore.kernel.org/r/20230330-hold_wakeref_for_active_vm-v1-1-baca712692f6@intel.com > --- > drivers/gpu/drm/i915/gt/intel_context.h | 15 +++++++++++---- > drivers/gpu/drm/i915/gt/intel_engine_pm.c | 9 +++++++++ > 2 files changed, 20 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h > index 0a8d553da3f439..48f888c3da083b 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context.h > +++ b/drivers/gpu/drm/i915/gt/intel_context.h > @@ -14,6 +14,7 @@ > #include "i915_drv.h" > #include "intel_context_types.h" > #include "intel_engine_types.h" > +#include "intel_gt_pm.h" > #include "intel_ring_types.h" > #include "intel_timeline_types.h" > #include "i915_trace.h" > @@ -207,8 +208,11 @@ void intel_context_exit_engine(struct intel_context *ce); > static inline void intel_context_enter(struct intel_context *ce) > { > lockdep_assert_held(&ce->timeline->mutex); > - if (!ce->active_count++) > - ce->ops->enter(ce); > + if (ce->active_count++) > + return; > + > + ce->ops->enter(ce); > + intel_gt_pm_get(ce->vm->gt); > } > > static inline void intel_context_mark_active(struct intel_context *ce) > @@ -222,8 +226,11 @@ static inline void intel_context_exit(struct intel_context *ce) > { > lockdep_assert_held(&ce->timeline->mutex); > GEM_BUG_ON(!ce->active_count); > - if (!--ce->active_count) > - ce->ops->exit(ce); > + if (--ce->active_count) > + return; > + > + intel_gt_pm_put_async(ce->vm->gt); > + ce->ops->exit(ce); > } > > static inline struct intel_context *intel_context_get(struct intel_context *ce) > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c > index e971b153fda976..ee531a5c142c77 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c > +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c > @@ -114,6 +114,15 @@ __queue_and_release_pm(struct i915_request *rq, > > ENGINE_TRACE(engine, "parking\n"); > > + /* > + * Open coded one half of intel_context_enter, which we have to omit > + * here (see the large comment below) and because the other part must > + * not be called due constructing directly with __i915_request_create > + * which increments active count via intel_context_mark_active. > + */ > + GEM_BUG_ON(rq->context->active_count != 1); > + __intel_gt_pm_get(engine->gt); > + > /* > * We have to serialise all potential retirement paths with our > * submission, as we don't want to underflow either the
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Regards,
Tvrtko
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