drm/i915: Stop tracking execlists retired requests
With the previous patch having extended the pinned lifetime of
contexts by referencing the previous context from the current
request until the latter is retired (completed by the GPU),
we can now remove usage of execlist retired queue entirely.
This is because the above now guarantees that all execlist
object access requirements are satisfied by this new tracking,
and we can stop taking additional references and stop keeping
request on the execlists retired queue.
The latter was a source of significant scalability issues in
the driver causing performance hits on some tests. Most
dramatical of which was igt/gem_close_race which had run time
in tens of minutes which is now reduced to tens of seconds.
Signed-off-by: Tvrtko Ursulin <tvrtko@ursulin.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-24-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 72cd084..411201f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2874,13 +2874,7 @@
/* Ensure irq handler finishes or is cancelled. */
tasklet_kill(&engine->irq_tasklet);
- spin_lock_bh(&engine->execlist_lock);
- /* list_splice_tail_init checks for empty lists */
- list_splice_tail_init(&engine->execlist_queue,
- &engine->execlist_retired_req_list);
- spin_unlock_bh(&engine->execlist_lock);
-
- intel_execlists_retire_requests(engine);
+ intel_execlists_cancel_requests(engine);
}
/*
@@ -3004,8 +2998,6 @@
spin_lock_bh(&engine->execlist_lock);
idle &= list_empty(&engine->execlist_queue);
spin_unlock_bh(&engine->execlist_lock);
-
- intel_execlists_retire_requests(engine);
}
}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index dc25cfe..874c251 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -435,8 +435,8 @@
/* Same ctx: ignore first request, as second request
* will update tail past first request's workload */
cursor->elsp_submitted = req0->elsp_submitted;
- list_move_tail(&req0->execlist_link,
- &engine->execlist_retired_req_list);
+ list_del(&req0->execlist_link);
+ i915_gem_request_unreference(req0);
req0 = cursor;
} else {
req1 = cursor;
@@ -468,7 +468,7 @@
}
static unsigned int
-execlists_check_remove_request(struct intel_engine_cs *engine, u32 request_id)
+execlists_check_remove_request(struct intel_engine_cs *engine, u32 ctx_id)
{
struct drm_i915_gem_request *head_req;
@@ -478,19 +478,16 @@
struct drm_i915_gem_request,
execlist_link);
- if (!head_req)
- return 0;
-
- if (unlikely(head_req->ctx_hw_id != request_id))
- return 0;
+ if (WARN_ON(!head_req || (head_req->ctx_hw_id != ctx_id)))
+ return 0;
WARN(head_req->elsp_submitted == 0, "Never submitted head request\n");
if (--head_req->elsp_submitted > 0)
return 0;
- list_move_tail(&head_req->execlist_link,
- &engine->execlist_retired_req_list);
+ list_del(&head_req->execlist_link);
+ i915_gem_request_unreference(head_req);
return 1;
}
@@ -594,9 +591,6 @@
struct drm_i915_gem_request *cursor;
int num_elements = 0;
- intel_lr_context_pin(request->ctx, request->engine);
- i915_gem_request_reference(request);
-
spin_lock_bh(&engine->execlist_lock);
list_for_each_entry(cursor, &engine->execlist_queue, execlist_link)
@@ -613,11 +607,12 @@
if (request->ctx == tail_req->ctx) {
WARN(tail_req->elsp_submitted != 0,
"More than 2 already-submitted reqs queued\n");
- list_move_tail(&tail_req->execlist_link,
- &engine->execlist_retired_req_list);
+ list_del(&tail_req->execlist_link);
+ i915_gem_request_unreference(tail_req);
}
}
+ i915_gem_request_reference(request);
list_add_tail(&request->execlist_link, &engine->execlist_queue);
request->ctx_hw_id = request->ctx->hw_id;
if (num_elements == 0)
@@ -883,23 +878,18 @@
return 0;
}
-void intel_execlists_retire_requests(struct intel_engine_cs *engine)
+void intel_execlists_cancel_requests(struct intel_engine_cs *engine)
{
struct drm_i915_gem_request *req, *tmp;
- struct list_head retired_list;
+ LIST_HEAD(cancel_list);
WARN_ON(!mutex_is_locked(&engine->dev->struct_mutex));
- if (list_empty(&engine->execlist_retired_req_list))
- return;
- INIT_LIST_HEAD(&retired_list);
spin_lock_bh(&engine->execlist_lock);
- list_replace_init(&engine->execlist_retired_req_list, &retired_list);
+ list_replace_init(&engine->execlist_queue, &cancel_list);
spin_unlock_bh(&engine->execlist_lock);
- list_for_each_entry_safe(req, tmp, &retired_list, execlist_link) {
- intel_lr_context_unpin(req->ctx, engine);
-
+ list_for_each_entry_safe(req, tmp, &cancel_list, execlist_link) {
list_del(&req->execlist_link);
i915_gem_request_unreference(req);
}
@@ -1993,7 +1983,6 @@
INIT_LIST_HEAD(&engine->buffers);
INIT_LIST_HEAD(&engine->execlist_queue);
- INIT_LIST_HEAD(&engine->execlist_retired_req_list);
spin_lock_init(&engine->execlist_lock);
tasklet_init(&engine->irq_tasklet,
diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index 28ff324..229b8a9 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -118,6 +118,6 @@
struct drm_i915_gem_execbuffer2 *args,
struct list_head *vmas);
-void intel_execlists_retire_requests(struct intel_engine_cs *engine);
+void intel_execlists_cancel_requests(struct intel_engine_cs *engine);
#endif /* _INTEL_LRC_H_ */
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 038914c..7023e88 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -266,7 +266,6 @@
struct tasklet_struct irq_tasklet;
spinlock_t execlist_lock; /* used inside tasklet, use spin_lock_bh */
struct list_head execlist_queue;
- struct list_head execlist_retired_req_list;
unsigned int fw_domains;
unsigned int next_context_status_buffer;
unsigned int idle_lite_restore_wa;