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>
Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_request.c | 23 ++++++++++++++---------
drivers/gpu/drm/i915/i915_request.h | 2 +-
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index c282719ad3ac..877eaaccba81 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);
@@ -189,14 +188,14 @@ 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);
/*
@@ -209,7 +208,7 @@ 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);
+ init_llist_head(&rq->execute_cb);
}
static inline void
@@ -327,7 +326,7 @@ 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);
@@ -357,6 +356,12 @@ void i915_request_retire_upto(struct i915_request *rq)
} while (i915_request_retire(tmp) && tmp != rq);
}
+static void __llist_add(struct llist_node *node, struct llist_head *head)
+{
+ node->next = head->first;
+ head->first = node;
+}
+
static int
__await_execution(struct i915_request *rq,
struct i915_request *signal,
@@ -395,7 +400,7 @@ __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);
+ __llist_add(&cb->work.llnode, &signal->execute_cb);
}
spin_unlock_irq(&signal->lock);
@@ -704,7 +709,7 @@ 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 *
@@ -794,7 +799,7 @@ __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
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
