linux-kernel - [PATCH] mm/damon: Prevent unnecessary age reset for regions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1691401475-3796-1-git-send-email-hyeongtak.ji@gmail.com>
Date:   Mon,  7 Aug 2023 18:44:35 +0900
From:   Hyeongtak Ji <hyeongtak.ji@...il.com>
To:     sj@...nel.org, akpm@...ux-foundation.org
Cc:     damon@...ts.linux.dev, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        Hyeongtak Ji <hyeongtak.ji@...il.com>,
        Hyeongtak Ji <hyeongtak.ji@...com>
Subject: [PATCH] mm/damon: Prevent unnecessary age reset for regions

DAMON resets the age of each region after applying each scheme,
regardless of whether the scheme has been successfully applied.

This patch adds a simple condition to prevent the age of regions from
being reset when schemes have not been actually applied.

Signed-off-by: Hyeongtak Ji <hyeongtak.ji@...com>
---
 mm/damon/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 91cff7f2997e..4044fcf18ac1 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -908,7 +908,7 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t,
 			quota->charge_addr_from = r->ar.end + 1;
 		}
 	}
-	if (s->action != DAMOS_STAT)
+	if (s->action != DAMOS_STAT && sz_applied > 0)
 		r->age = 0;
 
 update_stat:
-- 
2.7.4