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  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:	Sun, 19 Jun 2016 09:48:47 +0800
From:	Wenwei Tao <wwtao0320@....com>
To:	akpm@...ux-foundation.org, mgorman@...hsingularity.net
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	ww.tao0320@...il.com
Subject: [RFC PATCH 2/3] mm, page_alloc: get page migreate type again when related to highatomic

From: Wenwei Tao <ww.tao0320@...il.com>

The migratetype might get staled, pages might have become highatomic when
we try to free them to the allocator, we might not want to put highatomic
pages into other buddy lists, since they are reserved only for atomic high
order use. And also highatomic pages could have been unreserved,
put them into the hightatomic buddy list might exceed the limit of
highatomic pages. So get the pages migreate type again to put them into
the right lists.

Signed-off-by: Wenwei Tao <ww.tao0320@...il.com>
---
 mm/page_alloc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 19f9e76..b72b771 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1079,9 +1079,11 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 	int batch_free = 0;
 	unsigned long nr_scanned;
 	bool isolated_pageblocks;
+	bool reserved_highatomic;
 
 	spin_lock(&zone->lock);
 	isolated_pageblocks = has_isolate_pageblock(zone);
+	reserved_highatomic = !!zone->nr_reserved_highatomic;
 	nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
 	if (nr_scanned)
 		__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
@@ -1118,8 +1120,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 			mt = get_pcppage_migratetype(page);
 			/* MIGRATE_ISOLATE page should not go to pcplists */
 			VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
+			VM_BUG_ON_PAGE(mt == MIGRATE_HIGHATOMIC, page);
 			/* Pageblock could have been isolated meanwhile */
-			if (unlikely(isolated_pageblocks))
+			if (unlikely(isolated_pageblocks ||
+					reserved_highatomic))
 				mt = get_pageblock_migratetype(page);
 
 			if (bulkfree_pcp_prepare(page))
@@ -1144,7 +1148,9 @@ static void free_one_page(struct zone *zone,
 		__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
 
 	if (unlikely(has_isolate_pageblock(zone) ||
-		is_migrate_isolate(migratetype))) {
+		zone->nr_reserved_highatomic ||
+		is_migrate_isolate(migratetype) ||
+		migratetype == MIGRATE_HIGHATOMIC)) {
 		migratetype = get_pfnblock_migratetype(page, pfn);
 	}
 	__free_one_page(page, pfn, zone, order, migratetype);
-- 
1.8.3.1


Powered by blists - more mailing lists