| Message ID | 20200716172845.31427-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbs | expand |
On 16/07/2020 18:28, Chris Wilson wrote: > After staring at the breadcrumb enabling/cancellation and coming to the > conclusion that the cause of the mysterious stale breadcrumbs must the > act of submitting a completed requests, we can then redirect those > completed requests onto a dedicated signaled_list at the time of > construction and so eliminate intel_engine_transfer_stale_breadcrumbs(). > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 44 +++++++-------------- > drivers/gpu/drm/i915/gt/intel_engine.h | 3 -- > drivers/gpu/drm/i915/gt/intel_lrc.c | 15 ------- > drivers/gpu/drm/i915/i915_request.c | 5 +-- > 4 files changed, 17 insertions(+), 50 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c > index a0f52417238c..11660bef1545 100644 > --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c > +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c > @@ -144,7 +144,6 @@ static void add_retire(struct intel_breadcrumbs *b, struct intel_timeline *tl) > > static void __signal_request(struct i915_request *rq, struct list_head *signals) > { > - GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)); > clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); > > if (!__dma_fence_signal(&rq->fence)) > @@ -278,32 +277,6 @@ void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine) > spin_unlock_irqrestore(&b->irq_lock, flags); > } > > -void intel_engine_transfer_stale_breadcrumbs(struct intel_engine_cs *engine, > - struct intel_context *ce) > -{ > - struct intel_breadcrumbs *b = &engine->breadcrumbs; > - unsigned long flags; > - > - spin_lock_irqsave(&b->irq_lock, flags); > - if (!list_empty(&ce->signals)) { > - struct i915_request *rq, *next; > - > - /* Queue for executing the signal callbacks in the irq_work */ > - list_for_each_entry_safe(rq, next, &ce->signals, signal_link) { > - GEM_BUG_ON(rq->engine != engine); > - GEM_BUG_ON(!__request_completed(rq)); > - > - __signal_request(rq, &b->signaled_requests); > - } > - > - INIT_LIST_HEAD(&ce->signals); > - list_del_init(&ce->signal_link); > - > - irq_work_queue(&b->irq_work); > - } > - spin_unlock_irqrestore(&b->irq_lock, flags); > -} > - > void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine) > { > } > @@ -317,6 +290,17 @@ static void insert_breadcrumb(struct i915_request *rq, > if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) > return; > > + /* > + * If the request is already completed, we can transfer it > + * straight onto a signaled list, and queue the irq worker for > + * its signal completion. > + */ > + if (__request_completed(rq)) { > + __signal_request(rq, &b->signaled_requests); > + irq_work_queue(&b->irq_work); > + return; > + } > + > __intel_breadcrumbs_arm_irq(b); > > /* > @@ -341,8 +325,10 @@ static void insert_breadcrumb(struct i915_request *rq, > break; > } > list_add(&rq->signal_link, pos); > - if (pos == &ce->signals) /* catch transitions from empty list */ > + if (pos == &ce->signals) { /* catch transitions from empty list */ > list_move_tail(&ce->signal_link, &b->signalers); > + irq_work_queue(&b->irq_work); /* check after enabling irq */ > + } > GEM_BUG_ON(!check_signal_order(ce, rq)); > > set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); > @@ -401,7 +387,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) > > spin_unlock(&b->irq_lock); > > - return !__request_completed(rq); > + return true; Maybe my in head diff apply is failing me, but I think there isn't a "return false" path left so could be made a return void function. Regards, Tvrtko > } > > void i915_request_cancel_breadcrumb(struct i915_request *rq) > diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h > index a9249a23903a..faf00a353e25 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine.h > +++ b/drivers/gpu/drm/i915/gt/intel_engine.h > @@ -237,9 +237,6 @@ intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine) > void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine); > void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine); > > -void intel_engine_transfer_stale_breadcrumbs(struct intel_engine_cs *engine, > - struct intel_context *ce); > - > void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine, > struct drm_printer *p); > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 21c16e31c4fe..88a5c155154d 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -1805,18 +1805,6 @@ static bool virtual_matches(const struct virtual_engine *ve, > return true; > } > > -static void virtual_xfer_breadcrumbs(struct virtual_engine *ve) > -{ > - /* > - * All the outstanding signals on ve->siblings[0] must have > - * been completed, just pending the interrupt handler. As those > - * signals still refer to the old sibling (via rq->engine), we must > - * transfer those to the old irq_worker to keep our locking > - * consistent. > - */ > - intel_engine_transfer_stale_breadcrumbs(ve->siblings[0], &ve->context); > -} > - > #define for_each_waiter(p__, rq__) \ > list_for_each_entry_lockless(p__, \ > &(rq__)->sched.waiters_list, \ > @@ -2275,9 +2263,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine) > virtual_update_register_offsets(regs, > engine); > > - if (!list_empty(&ve->context.signals)) > - virtual_xfer_breadcrumbs(ve); > - > /* > * Move the bound engine to the top of the list > * for future execution. We then kick this > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c > index fc25382e1201..d88f046ccbdd 100644 > --- a/drivers/gpu/drm/i915/i915_request.c > +++ b/drivers/gpu/drm/i915/i915_request.c > @@ -609,9 +609,8 @@ bool __i915_request_submit(struct i915_request *request) > */ > __notify_execute_cb_irq(request); > > - if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags) && > - !i915_request_enable_breadcrumb(request)) > - intel_engine_signal_breadcrumbs(engine); > + if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) > + i915_request_enable_breadcrumb(request); > > return result; > } >
Quoting Tvrtko Ursulin (2020-07-17 09:13:21) > > On 16/07/2020 18:28, Chris Wilson wrote: > > @@ -341,8 +325,10 @@ static void insert_breadcrumb(struct i915_request *rq, > > break; > > } > > list_add(&rq->signal_link, pos); > > - if (pos == &ce->signals) /* catch transitions from empty list */ > > + if (pos == &ce->signals) { /* catch transitions from empty list */ > > list_move_tail(&ce->signal_link, &b->signalers); > > + irq_work_queue(&b->irq_work); /* check after enabling irq */ > > + } > > GEM_BUG_ON(!check_signal_order(ce, rq)); > > > > set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); > > @@ -401,7 +387,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) > > > > spin_unlock(&b->irq_lock); > > > > - return !__request_completed(rq); > > + return true; > > Maybe my in head diff apply is failing me, but I think there isn't a > "return false" path left so could be made a return void function. There is no return false path anymore (since we always queue the worker which should run immediately after dma_fence_enable_signaling if necessary, that seemed to be more sensible than conditionally using the worker, I also looked at splitting enable_breadcrumb and activate_breadcrumb, but the two paths are more similar than not), I kept it bool so that it matched i915_fence_enable_signaling. -Chris
On 17/07/2020 09:24, Chris Wilson wrote: > Quoting Tvrtko Ursulin (2020-07-17 09:13:21) >> >> On 16/07/2020 18:28, Chris Wilson wrote: >>> @@ -341,8 +325,10 @@ static void insert_breadcrumb(struct i915_request *rq, >>> break; >>> } >>> list_add(&rq->signal_link, pos); >>> - if (pos == &ce->signals) /* catch transitions from empty list */ >>> + if (pos == &ce->signals) { /* catch transitions from empty list */ >>> list_move_tail(&ce->signal_link, &b->signalers); >>> + irq_work_queue(&b->irq_work); /* check after enabling irq */ >>> + } >>> GEM_BUG_ON(!check_signal_order(ce, rq)); >>> >>> set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); >>> @@ -401,7 +387,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) >>> >>> spin_unlock(&b->irq_lock); >>> >>> - return !__request_completed(rq); >>> + return true; >> >> Maybe my in head diff apply is failing me, but I think there isn't a >> "return false" path left so could be made a return void function. > > There is no return false path anymore (since we always queue the worker > which should run immediately after dma_fence_enable_signaling if > necessary, that seemed to be more sensible than conditionally using the > worker, I also looked at splitting enable_breadcrumb and > activate_breadcrumb, but the two paths are more similar than not), I > kept it bool so that it matched i915_fence_enable_signaling. It's a bit questionable, in this case it would probably be better to have explicit "return true" in i915_fence_enable_signaling. But it is a minor point anyway and bugfix trumps it. Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index a0f52417238c..11660bef1545 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -144,7 +144,6 @@ static void add_retire(struct intel_breadcrumbs *b, struct intel_timeline *tl) static void __signal_request(struct i915_request *rq, struct list_head *signals) { - GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)); clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); if (!__dma_fence_signal(&rq->fence)) @@ -278,32 +277,6 @@ void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine) spin_unlock_irqrestore(&b->irq_lock, flags); } -void intel_engine_transfer_stale_breadcrumbs(struct intel_engine_cs *engine, - struct intel_context *ce) -{ - struct intel_breadcrumbs *b = &engine->breadcrumbs; - unsigned long flags; - - spin_lock_irqsave(&b->irq_lock, flags); - if (!list_empty(&ce->signals)) { - struct i915_request *rq, *next; - - /* Queue for executing the signal callbacks in the irq_work */ - list_for_each_entry_safe(rq, next, &ce->signals, signal_link) { - GEM_BUG_ON(rq->engine != engine); - GEM_BUG_ON(!__request_completed(rq)); - - __signal_request(rq, &b->signaled_requests); - } - - INIT_LIST_HEAD(&ce->signals); - list_del_init(&ce->signal_link); - - irq_work_queue(&b->irq_work); - } - spin_unlock_irqrestore(&b->irq_lock, flags); -} - void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine) { } @@ -317,6 +290,17 @@ static void insert_breadcrumb(struct i915_request *rq, if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) return; + /* + * If the request is already completed, we can transfer it + * straight onto a signaled list, and queue the irq worker for + * its signal completion. + */ + if (__request_completed(rq)) { + __signal_request(rq, &b->signaled_requests); + irq_work_queue(&b->irq_work); + return; + } + __intel_breadcrumbs_arm_irq(b); /* @@ -341,8 +325,10 @@ static void insert_breadcrumb(struct i915_request *rq, break; } list_add(&rq->signal_link, pos); - if (pos == &ce->signals) /* catch transitions from empty list */ + if (pos == &ce->signals) { /* catch transitions from empty list */ list_move_tail(&ce->signal_link, &b->signalers); + irq_work_queue(&b->irq_work); /* check after enabling irq */ + } GEM_BUG_ON(!check_signal_order(ce, rq)); set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); @@ -401,7 +387,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) spin_unlock(&b->irq_lock); - return !__request_completed(rq); + return true; } void i915_request_cancel_breadcrumb(struct i915_request *rq) diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h index a9249a23903a..faf00a353e25 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine.h +++ b/drivers/gpu/drm/i915/gt/intel_engine.h @@ -237,9 +237,6 @@ intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine) void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine); void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine); -void intel_engine_transfer_stale_breadcrumbs(struct intel_engine_cs *engine, - struct intel_context *ce); - void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine, struct drm_printer *p); diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 21c16e31c4fe..88a5c155154d 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1805,18 +1805,6 @@ static bool virtual_matches(const struct virtual_engine *ve, return true; } -static void virtual_xfer_breadcrumbs(struct virtual_engine *ve) -{ - /* - * All the outstanding signals on ve->siblings[0] must have - * been completed, just pending the interrupt handler. As those - * signals still refer to the old sibling (via rq->engine), we must - * transfer those to the old irq_worker to keep our locking - * consistent. - */ - intel_engine_transfer_stale_breadcrumbs(ve->siblings[0], &ve->context); -} - #define for_each_waiter(p__, rq__) \ list_for_each_entry_lockless(p__, \ &(rq__)->sched.waiters_list, \ @@ -2275,9 +2263,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine) virtual_update_register_offsets(regs, engine); - if (!list_empty(&ve->context.signals)) - virtual_xfer_breadcrumbs(ve); - /* * Move the bound engine to the top of the list * for future execution. We then kick this diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index fc25382e1201..d88f046ccbdd 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -609,9 +609,8 @@ bool __i915_request_submit(struct i915_request *request) */ __notify_execute_cb_irq(request); - if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags) && - !i915_request_enable_breadcrumb(request)) - intel_engine_signal_breadcrumbs(engine); + if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) + i915_request_enable_breadcrumb(request); return result; }
After staring at the breadcrumb enabling/cancellation and coming to the conclusion that the cause of the mysterious stale breadcrumbs must the act of submitting a completed requests, we can then redirect those completed requests onto a dedicated signaled_list at the time of construction and so eliminate intel_engine_transfer_stale_breadcrumbs(). Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> --- drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 44 +++++++-------------- drivers/gpu/drm/i915/gt/intel_engine.h | 3 -- drivers/gpu/drm/i915/gt/intel_lrc.c | 15 ------- drivers/gpu/drm/i915/i915_request.c | 5 +-- 4 files changed, 17 insertions(+), 50 deletions(-)