Merge tag 'sound-5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

[linux.git] / drivers / iommu / iova.c

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 3e1a8a6755723a927a7942a7429ab7e6c19a0027..41c605b0058f9615c2dbdd83f1de2404a9b1d255 100644 (file)
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -577,7 +577,9 @@ void queue_iova(struct iova_domain *iovad,
 
        spin_unlock_irqrestore(&fq->lock, flags);
 
-       if (atomic_cmpxchg(&iovad->fq_timer_on, 0, 1) == 0)
+       /* Avoid false sharing as much as possible. */
+       if (!atomic_read(&iovad->fq_timer_on) &&
+           !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1))
                mod_timer(&iovad->fq_timer,
                          jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT));
 }