Reduce the irq_work llist for attaching the callbacks to the signal for
both smaller structs (two fewer pointers!) and simpler [debug] code:
Function old new delta
irq_execute_cb 35 34 -1
__igt_breadcrumbs_smoketest 1684 1682 -2
i915_request_retire 2003 1996 -7
__i915_request_create 1047 1040 -7
__notify_execute_cb 135 126 -9
__i915_request_ctor 188 178 -10
__await_execution.part.constprop 451 440 -11
igt_wait_request 924 714 -210
One minor artifact is that the order of cb exection is reversed. No
current use cases are affected by that change.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_request.c | 18 +++++++++---------
drivers/gpu/drm/i915/i915_request.h | 2 +-
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 526c1e9acbd5..25571a342468 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -42,7 +42,6 @@
#include "intel_pm.h"
struct execute_cb {
- struct list_head link;
struct irq_work work;
struct i915_sw_fence *fence;
void (*hook)(struct i915_request *rq, struct dma_fence *signal);
@@ -158,14 +157,14 @@ static void irq_execute_cb_hook(struct irq_work *wrk)
static void __notify_execute_cb(struct i915_request *rq)
{
- struct execute_cb *cb;
+ struct execute_cb *cb, *cn;
lockdep_assert_held(&rq->lock);
- if (list_empty(&rq->execute_cb))
+ if (llist_empty(&rq->execute_cb))
return;
- list_for_each_entry(cb, &rq->execute_cb, link)
+ llist_for_each_entry_safe(cb, cn, rq->execute_cb.first, work.llnode)
irq_work_queue(&cb->work);
/*
@@ -178,7 +177,7 @@ static void __notify_execute_cb(struct i915_request *rq)
* preempt-to-idle cycle on the target engine, all the while the
* master execute_cb may refire.
*/
- INIT_LIST_HEAD(&rq->execute_cb);
+ rq->execute_cb.first = NULL;
}
static inline void
@@ -296,7 +295,7 @@ bool i915_request_retire(struct i915_request *rq)
set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
__notify_execute_cb(rq);
}
- GEM_BUG_ON(!list_empty(&rq->execute_cb));
+ GEM_BUG_ON(!llist_empty(&rq->execute_cb));
spin_unlock_irq(&rq->lock);
remove_from_client(rq);
@@ -364,7 +363,8 @@ __await_execution(struct i915_request *rq,
i915_sw_fence_complete(cb->fence);
kmem_cache_free(global.slab_execute_cbs, cb);
} else {
- list_add_tail(&cb->link, &signal->execute_cb);
+ cb->work.llnode.next = signal->execute_cb.first;
+ signal->execute_cb.first = &cb->work.llnode;
}
spin_unlock_irq(&signal->lock);
@@ -673,7 +673,7 @@ static void __i915_request_ctor(void *arg)
rq->file_priv = NULL;
rq->capture_list = NULL;
- INIT_LIST_HEAD(&rq->execute_cb);
+ init_llist_head(&rq->execute_cb);
}
struct i915_request *
@@ -763,7 +763,7 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
rq->batch = NULL;
GEM_BUG_ON(rq->file_priv);
GEM_BUG_ON(rq->capture_list);
- GEM_BUG_ON(!list_empty(&rq->execute_cb));
+ GEM_BUG_ON(!llist_empty(&rq->execute_cb));
/*
* Reserve space in the ring buffer for all the commands required to
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 8ec7ee4dbadc..5d4709a3dace 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -214,7 +214,7 @@ struct i915_request {
ktime_t emitted;
} duration;
};
- struct list_head execute_cb;
+ struct llist_head execute_cb;
struct i915_sw_fence semaphore;
/*
--
2.20.1
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