Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit1d91df8

Browse files
JoonsooKimtorvalds
authored andcommitted
mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIs
memalloc_nocma_{save/restore} APIs can be used to skip page allocationon CMA area, but, there is a missing case and the page on CMA area couldbe allocated even if APIs are used. This patch handles this case to fixthe potential issue.For now, these APIs are used to prevent long-term pinning on the CMApage. When the long-term pinning is requested on the CMA page, it ismigrated to the non-CMA page before pinning. This non-CMA page isallocated by using memalloc_nocma_{save/restore} APIs. If APIs doesn'twork as intended, the CMA page is allocated and it is pinned for a longtime. This long-term pin for the CMA page causes cma_alloc() failureand it could result in wrong behaviour on the device driver who uses thecma_alloc().Missing case is an allocation from the pcplist. MIGRATE_MOVABLE pcplistcould have the pages on CMA area so we need to skip it if ALLOC_CMAisn't specified.Fixes:8510e69 (mm/page_alloc: fix memalloc_nocma_{save/restore} APIs)Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>Signed-off-by: Andrew Morton <akpm@linux-foundation.org>Acked-by: Vlastimil Babka <vbabka@suse.cz>Acked-by: Michal Hocko <mhocko@suse.com>Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>Cc: Mel Gorman <mgorman@techsingularity.net>Link:https://lkml.kernel.org/r/1601429472-12599-1-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent484cfac commit1d91df8

File tree

1 file changed

+16
-3
lines changed

1 file changed

+16
-3
lines changed

‎mm/page_alloc.c‎

Lines changed: 16 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -3367,9 +3367,16 @@ struct page *rmqueue(struct zone *preferred_zone,
33673367
structpage*page;
33683368

33693369
if (likely(order==0)) {
3370-
page=rmqueue_pcplist(preferred_zone,zone,gfp_flags,
3370+
/*
3371+
* MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3372+
* we need to skip it when CMA area isn't allowed.
3373+
*/
3374+
if (!IS_ENABLED(CONFIG_CMA)||alloc_flags&ALLOC_CMA||
3375+
migratetype!=MIGRATE_MOVABLE) {
3376+
page=rmqueue_pcplist(preferred_zone,zone,gfp_flags,
33713377
migratetype,alloc_flags);
3372-
gotoout;
3378+
gotoout;
3379+
}
33733380
}
33743381

33753382
/*
@@ -3381,7 +3388,13 @@ struct page *rmqueue(struct zone *preferred_zone,
33813388

33823389
do {
33833390
page=NULL;
3384-
if (alloc_flags&ALLOC_HARDER) {
3391+
/*
3392+
* order-0 request can reach here when the pcplist is skipped
3393+
* due to non-CMA allocation context. HIGHATOMIC area is
3394+
* reserved for high-order atomic allocation, so order-0
3395+
* request should skip it.
3396+
*/
3397+
if (order>0&&alloc_flags&ALLOC_HARDER) {
33853398
page=__rmqueue_smallest(zone,order,MIGRATE_HIGHATOMIC);
33863399
if (page)
33873400
trace_mm_page_alloc_zone_locked(page,order,migratetype);

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp