The patch titled
Subject: z3fold: fix memory leak in kmem cache
has been added to the -mm tree. Its filename is
z3fold-fix-memory-leak-in-kmem-cache.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/z3fold-fix-memory-leak-in-kmem-cache.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/z3fold-fix-memory-leak-in-kmem-cache.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Vitaly Wool <vitalywool@xxxxxxxxx>
Subject: z3fold: fix memory leak in kmem cache
Currently there is a leak in init_z3fold_page() -- it allocates handles
from kmem cache even for headless pages, but then they are never used and
never freed, so eventually kmem cache may get exhausted. This patch
provides a fix for that.
Link: http://lkml.kernel.org/r/20190917185352.44cf285d3ebd9e64548de5de@xxxxxxxxx
Signed-off-by: Vitaly Wool <vitalywool@xxxxxxxxx>
Reported-by: Markus Linnala <markus.linnala@xxxxxxxxx>
Tested-by: Markus Linnala <markus.linnala@xxxxxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Henry Burns <henrywolfeburns@xxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/z3fold.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/mm/z3fold.c~z3fold-fix-memory-leak-in-kmem-cache
+++ a/mm/z3fold.c
@@ -295,14 +295,11 @@ static void z3fold_unregister_migration(
}
/* Initializes the z3fold header of a newly allocated z3fold page */
-static struct z3fold_header *init_z3fold_page(struct page *page,
+static struct z3fold_header *init_z3fold_page(struct page *page, bool headless,
struct z3fold_pool *pool, gfp_t gfp)
{
struct z3fold_header *zhdr = page_address(page);
- struct z3fold_buddy_slots *slots = alloc_slots(pool, gfp);
-
- if (!slots)
- return NULL;
+ struct z3fold_buddy_slots *slots;
INIT_LIST_HEAD(&page->lru);
clear_bit(PAGE_HEADLESS, &page->private);
@@ -310,6 +307,12 @@ static struct z3fold_header *init_z3fold
clear_bit(NEEDS_COMPACTING, &page->private);
clear_bit(PAGE_STALE, &page->private);
clear_bit(PAGE_CLAIMED, &page->private);
+ if (headless)
+ return zhdr;
+
+ slots = alloc_slots(pool, gfp);
+ if (!slots)
+ return NULL;
spin_lock_init(&zhdr->page_lock);
kref_init(&zhdr->refcount);
@@ -930,7 +933,7 @@ retry:
if (!page)
return -ENOMEM;
- zhdr = init_z3fold_page(page, pool, gfp);
+ zhdr = init_z3fold_page(page, bud == HEADLESS, pool, gfp);
if (!zhdr) {
__free_page(page);
return -ENOMEM;
_
Patches currently in -mm which might be from vitalywool@xxxxxxxxx are
revert-mm-z3foldc-fix-race-between-migration-and-destruction.patch
z3fold-fix-retry-mechanism-in-page-reclaim.patch
z3fold-fix-memory-leak-in-kmem-cache.patch
