This reverts commit 4e89dce725213d3d0b0475211b500eda4ef4bf2f.
We find that this patch has a great impact on performance. According to
our test: the iops decreases from 1655.6K to 893.5K, about half.
Hardware: 1 SAS expander with 12 SAS SSD
Command: Only the main parameters are listed.
fio bs=4k rw=read iodepth=128 cpus_allowed=0-127
Fixes: 4e89dce72521 ("iommu/iova: Retry from last rb tree node if iova search
fails")
Tested-by: Xiang Chen <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
---
drivers/iommu/iova.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index d20b8b333d30d17..f840c7207efbced 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -185,9 +185,8 @@ static int __alloc_and_insert_iova_range(struct iova_domain
*iovad,
struct rb_node *curr, *prev;
struct iova *curr_iova;
unsigned long flags;
- unsigned long new_pfn, retry_pfn;
+ unsigned long new_pfn;
unsigned long align_mask = ~0UL;
- unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn;
if (size_aligned)
align_mask <<= fls_long(size - 1);
@@ -200,25 +199,15 @@ static int __alloc_and_insert_iova_range(struct
iova_domain *iovad,
curr = __get_cached_rbnode(iovad, limit_pfn);
curr_iova = rb_entry(curr, struct iova, node);
- retry_pfn = curr_iova->pfn_hi + 1;
-
-retry:
do {
- high_pfn = min(high_pfn, curr_iova->pfn_lo);
- new_pfn = (high_pfn - size) & align_mask;
+ limit_pfn = min(limit_pfn, curr_iova->pfn_lo);
+ new_pfn = (limit_pfn - size) & align_mask;
prev = curr;
curr = rb_prev(curr);
curr_iova = rb_entry(curr, struct iova, node);
- } while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn);
-
- if (high_pfn < size || new_pfn < low_pfn) {
- if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) {
- high_pfn = limit_pfn;
- low_pfn = retry_pfn;
- curr = &iovad->anchor.node;
- curr_iova = rb_entry(curr, struct iova, node);
- goto retry;
- }
+ } while (curr && new_pfn <= curr_iova->pfn_hi);
+
+ if (limit_pfn < size || new_pfn < iovad->start_pfn) {
iovad->max32_alloc_size = size;
goto iova32_full;
}
--
1.8.3
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