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From:   Huangzhaoyang <huangzhaoyang@gmail.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Minchan Kim <minchan@kernel.org>,
        Zhaoyang Huang <zhaoyang.huang@unisoc.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] mm : bail out from psi memstall after submit_bio in swap_readpage
Date:   Tue,  7 Sep 2021 19:59:28 +0800
Message-Id: <1631015968-9779-1-git-send-email-huangzhaoyang@gmail.com>
Precedence: bulk

From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

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

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
 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