diff options
| author | Yuqi Jin <jinyuqi@huawei.com> | 2020-08-27 16:43:54 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2020-09-04 12:11:06 +0200 |
| commit | ba328f82613260a098de7b4aff58743cd8733507 (patch) | |
| tree | e5640a2d5d96de57d1d679e81804ac45f1fec9c7 /drivers/iommu/iova.c | |
| parent | 4604393ca0c6e4a73c04798c3f1d9878e70b7251 (diff) | |
iommu/iova: Replace cmpxchg with xchg in queue_iova
The performance of the atomic_xchg is better than atomic_cmpxchg because
no comparison is required. While the value of @fq_timer_on can only be 0
or 1. Let's use atomic_xchg instead of atomic_cmpxchg here because we
only need to check that the value changes from 0 to 1 or from 1 to 1.
Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Link: https://lore.kernel.org/r/1598517834-30275-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/iova.c')
| -rw-r--r-- | drivers/iommu/iova.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index 45a251da5453..30d969a4c5fd 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -579,7 +579,7 @@ void queue_iova(struct iova_domain *iovad, /* Avoid false sharing as much as possible. */ if (!atomic_read(&iovad->fq_timer_on) && - !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1)) + !atomic_xchg(&iovad->fq_timer_on, 1)) mod_timer(&iovad->fq_timer, jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT)); } |