[PATCH 5/5] md/raid5: Don't read ->active_stripes if it's not needed

From: Logan Gunthorpe
Date: Thu Aug 11 2022 - 13:19:19 EST


The atomic_read() is not needed in many cases so only do
the read after the first checks are done.

Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
drivers/md/raid5.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 7e7205bb40f1..0b73eeea1b19 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -789,15 +789,14 @@ struct stripe_request_ctx {
*/
static bool is_inactive_blocked(struct r5conf *conf, int hash)
{
- int active = atomic_read(&conf->active_stripes);
-
if (list_empty(conf->inactive_list + hash))
return false;

if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
return true;

- return active < (conf->max_nr_stripes * 3 / 4);
+ return (atomic_read(&conf->active_stripes) <
+ (conf->max_nr_stripes * 3 / 4));
}

struct stripe_head *raid5_get_active_stripe(struct r5conf *conf,
--
2.30.2