[PATCH v2] drm/xe/ufence: Kick ufence immediately when possible

[Nirmoy Das <nirmoy.das@intel.com>]

If the backing fence is signaled then signal ufence soon with
system_wq. This should reduce load from the xe ordered_wq and also
won't block signaling a ufence which doesn't require any serialization.

v2: fix system_wq typo

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1630
Cc: Matthew Auld <matthew.auld@intel.com>
gc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
---
 drivers/gpu/drm/xe/xe_sync.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
index c6cf227ead40..1a7907293088 100644
--- a/drivers/gpu/drm/xe/xe_sync.c
+++ b/drivers/gpu/drm/xe/xe_sync.c
@@ -89,10 +89,14 @@ static void user_fence_worker(struct work_struct *w)
 	user_fence_put(ufence);
 }
 
-static void kick_ufence(struct xe_user_fence *ufence, struct dma_fence *fence)
+static void kick_ufence(struct xe_user_fence *ufence, struct dma_fence *fence,
+			bool signaled)
 {
 	INIT_WORK(&ufence->worker, user_fence_worker);
-	queue_work(ufence->xe->ordered_wq, &ufence->worker);
+	if (signaled)
+		queue_work(system_wq, &ufence->worker);
+	else
+		queue_work(ufence->xe->ordered_wq, &ufence->worker);
 	dma_fence_put(fence);
 }
 
@@ -100,7 +104,7 @@ static void user_fence_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
 {
 	struct xe_user_fence *ufence = container_of(cb, struct xe_user_fence, cb);
 
-	kick_ufence(ufence, fence);
+	kick_ufence(ufence, fence, false);
 }
 
 int xe_sync_entry_parse(struct xe_device *xe, struct xe_file *xef,
@@ -236,7 +240,7 @@ void xe_sync_entry_signal(struct xe_sync_entry *sync, struct dma_fence *fence)
 		err = dma_fence_add_callback(fence, &sync->ufence->cb,
 					     user_fence_cb);
 		if (err == -ENOENT) {
-			kick_ufence(sync->ufence, fence);
+			kick_ufence(sync->ufence, fence, true);
 		} else if (err) {
 			XE_WARN_ON("failed to add user fence");
 			user_fence_put(sync->ufence);
-- 
2.46.0