Adding Robin.
On Thu, Aug 27, 2020 at 04:43:54PM +0800, Shaokun Zhang wrote: > From: Yuqi Jin <jiny...@huawei.com> > > 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. > > Cc: Joerg Roedel <j...@8bytes.org> > Signed-off-by: Yuqi Jin <jiny...@huawei.com> > Signed-off-by: Shaokun Zhang <zhangshao...@hisilicon.com> > --- > drivers/iommu/iova.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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)); > } > -- > 2.7.4 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
