linux-kernel - [PATCH v2 1/2] mm: Cap zone movable's min wmark to small value

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]

Date:   Fri, 19 Aug 2022 17:30:24 +0800
From:   Wupeng Ma <mawupeng1@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <corbet@....net>, <mcgrof@...nel.org>, <keescook@...omium.org>,
        <yzaikin@...gle.com>, <songmuchun@...edance.com>,
        <mike.kravetz@...cle.com>, <osalvador@...e.de>, <rppt@...nel.org>,
        <surenb@...gle.com>, <mawupeng1@...wei.com>, <jsavitz@...hat.com>,
        <linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-mm@...ck.org>, <linux-fsdevel@...r.kernel.org>,
        <wangkefeng.wang@...wei.com>
Subject: [PATCH v2 1/2] mm: Cap zone movable's min wmark to small value

From: Ma Wupeng <mawupeng1@...wei.com>

Since min_free_kbytes is based on gfp_zone(GFP_USER) which does not include
zone movable. However zone movable will get its min share in
__setup_per_zone_wmarks() which does not make any sense.

And like highmem pages, __GFP_HIGH and PF_MEMALLOC allocations usually
don't need movable pages, so there is no need to assign min pages for zone
movable.

Let's cap pages_min for zone movable to a small value here just link
highmem pages.

Signed-off-by: Ma Wupeng <mawupeng1@...wei.com>
---
 mm/page_alloc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e5486d47406e..ff644205370f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8638,7 +8638,7 @@ static void __setup_per_zone_wmarks(void)
 
 	/* Calculate total number of !ZONE_HIGHMEM pages */
 	for_each_zone(zone) {
-		if (!is_highmem(zone))
+		if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE)
 			lowmem_pages += zone_managed_pages(zone);
 	}
 
@@ -8648,7 +8648,7 @@ static void __setup_per_zone_wmarks(void)
 		spin_lock_irqsave(&zone->lock, flags);
 		tmp = (u64)pages_min * zone_managed_pages(zone);
 		do_div(tmp, lowmem_pages);
-		if (is_highmem(zone)) {
+		if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) {
 			/*
 			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
 			 * need highmem pages, so cap pages_min to a small
-- 
2.25.1