[PATCH] mm : bail out from psi memstall after submit_bio in swap_readpage

[Huangzhaoyang]

From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>

It doesn't make sense to count IO time into psi memstall. Bail out after
bio submitted.

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
---
 mm/page_io.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index c493ce9..1d131fc 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -423,6 +423,7 @@ int swap_readpage(struct page *page, bool synchronous)
 	count_vm_event(PSWPIN);
 	bio_get(bio);
 	qc = submit_bio(bio);
+	psi_memstall_leave(&pflags);
 	while (synchronous) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		if (!READ_ONCE(bio->bi_private))
@@ -433,7 +434,7 @@ int swap_readpage(struct page *page, bool synchronous)
 	}
 	__set_current_state(TASK_RUNNING);
 	bio_put(bio);
-
+	return ret;
 out:
 	psi_memstall_leave(&pflags);
 	return ret;
-- 
1.9.1