On 29/11/2019 00:48, Cong Wang wrote:
If the maganize is empty, iova_magazine_free_pfns() should
magazine
be a nop, however it misses the case of mag->size==0. So we
should just call iova_magazine_empty().
This should reduce the contention on iovad->iova_rbtree_lock
a little bit.
Cc: Joerg Roedel <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
---
drivers/iommu/iova.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index cb473ddce4cf..184d4c0e20b5 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -797,13 +797,23 @@ static void iova_magazine_free(struct iova_magazine *mag)
kfree(mag);
}
+static bool iova_magazine_full(struct iova_magazine *mag)
+{
+ return (mag && mag->size == IOVA_MAG_SIZE);
+}
+
+static bool iova_magazine_empty(struct iova_magazine *mag)
+{
+ return (!mag || mag->size == 0);
+}
+
static void
iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
{
unsigned long flags;
int i;
- if (!mag)
+ if (iova_magazine_empty(mag))
The only hot path we this call is
__iova_rcache_insert()->iova_magazine_free_pfns(mag_to_free) and
mag_to_free is full in this case, so I am sure how the additional check
helps, right?
Thanks,
John
return;
spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
@@ -820,16 +830,6 @@ iova_magazine_free_pfns(struct iova_magazine *mag, struct
iova_domain *iovad)
mag->size = 0;
}
-static bool iova_magazine_full(struct iova_magazine *mag)
-{
- return (mag && mag->size == IOVA_MAG_SIZE);
-}
-
-static bool iova_magazine_empty(struct iova_magazine *mag)
-{
- return (!mag || mag->size == 0);
-}
-
static unsigned long iova_magazine_pop(struct iova_magazine *mag,
unsigned long limit_pfn)
{
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