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-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20220418141253.24298-13-linmiaohe@huawei.com>
Date:   Mon, 18 Apr 2022 22:12:53 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <vbabka@...e.cz>, <pintu@...eaurora.org>,
        <charante@...eaurora.org>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>, <linmiaohe@...wei.com>
Subject: [PATCH 12/12] mm: compaction: make sure highest is above the min_pfn

It's not guaranteed that highest will be above the min_pfn. If highest is
below the min_pfn, migrate_pfn and free_pfn can meet prematurely and lead
to some useless work. Make sure highest is above min_pfn to avoid making
a futile effort.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/compaction.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 609a76d7e051..65970107b789 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1532,7 +1532,7 @@ fast_isolate_freepages(struct compact_control *cc)
 			 * not found, be pessimistic for direct compaction
 			 * and use the min mark.
 			 */
-			if (highest) {
+			if (highest >= min_pfn) {
 				page = pfn_to_page(highest);
 				cc->free_pfn = highest;
 			} else {
-- 
2.23.0

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ