[PATCH v2 2/2] drm/amdkfd: Slighly optimize 'init_doorbell_bitmap()'

Christophe JAILLET christophe.jaillet at wanadoo.fr
Tue Nov 23 20:46:58 UTC 2021


The 'doorbell_bitmap' bitmap has just been allocated. So we can use the
non-atomic '__set_bit()' function to save a few cycles as no concurrent
access can happen.

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet at wanadoo.fr>
---
bitmap_set() could certainly also be use, but range checking would be
tricky.

v1 --> v2: No change
---
 drivers/gpu/drm/amd/amdkfd/kfd_process.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 67bb1654becc..9158f9754a24 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1446,9 +1446,9 @@ static int init_doorbell_bitmap(struct qcm_process_device *qpd,
 
 	for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
 		if (i >= range_start && i <= range_end) {
-			set_bit(i, qpd->doorbell_bitmap);
-			set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
-				qpd->doorbell_bitmap);
+			__set_bit(i, qpd->doorbell_bitmap);
+			__set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
+				  qpd->doorbell_bitmap);
 		}
 	}
 
-- 
2.30.2



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