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* [PATCH v2] drm/xe: Remove unwanted mutex locking
@ 2024-05-29 18:33 Niranjana Vishwanathapura
  2024-05-29 18:49 ` Randhawa, Jagmeet
                   ` (9 more replies)
  0 siblings, 10 replies; 13+ messages in thread
From: Niranjana Vishwanathapura @ 2024-05-29 18:33 UTC (permalink / raw)
  To: intel-xe; +Cc: matthew.brost

Do not hold xef->exec_queue.lock mutex while parsing the xarray
xef->exec_queue.xa in xe_file_close() as it is not needed and
will cause an unwanted dependency between this lock and the vm->lock.

This lock protects the exec queue lookup and reference taking which
doesn't apply to this code path. When FD is closing, IOCTLs presumably
can't be modifying the xarray.

v2: Update commit text

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_device.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index f04b11e45c2d..4cca16f2d4ed 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -96,12 +96,11 @@ static void xe_file_close(struct drm_device *dev, struct drm_file *file)
 	struct xe_exec_queue *q;
 	unsigned long idx;
 
-	mutex_lock(&xef->exec_queue.lock);
+	/* No locking needed here */
 	xa_for_each(&xef->exec_queue.xa, idx, q) {
 		xe_exec_queue_kill(q);
 		xe_exec_queue_put(q);
 	}
-	mutex_unlock(&xef->exec_queue.lock);
 	xa_destroy(&xef->exec_queue.xa);
 	mutex_destroy(&xef->exec_queue.lock);
 	mutex_lock(&xef->vm.lock);
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2024-05-30  0:18 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-05-29 18:33 [PATCH v2] drm/xe: Remove unwanted mutex locking Niranjana Vishwanathapura
2024-05-29 18:49 ` Randhawa, Jagmeet
2024-05-29 20:15 ` ✓ CI.Patch_applied: success for drm/xe: Remove unwanted mutex locking (rev2) Patchwork
2024-05-29 20:15 ` ✓ CI.checkpatch: " Patchwork
2024-05-29 20:16 ` ✓ CI.KUnit: " Patchwork
2024-05-29 20:28 ` ✓ CI.Build: " Patchwork
2024-05-29 20:28 ` ✗ CI.Hooks: failure " Patchwork
2024-05-29 20:30 ` ✓ CI.checksparse: success " Patchwork
2024-05-29 20:49 ` [PATCH v2] drm/xe: Remove unwanted mutex locking Rodrigo Vivi
2024-05-29 21:28   ` Matthew Brost
2024-05-29 21:40   ` Niranjana Vishwanathapura
2024-05-29 20:54 ` ✓ CI.BAT: success for drm/xe: Remove unwanted mutex locking (rev2) Patchwork
2024-05-30  0:18 ` ✗ CI.FULL: failure " Patchwork

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