The patch titled
Subject: mm/z3fold.c: fix wrong handling of headless pages
has been added to the -mm tree. Its filename is
z3fold-fix-wrong-handling-of-headless-pages.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/z3fold-fix-wrong-handling-of-headless-pages.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/z3fold-fix-wrong-handling-of-headless-pages.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** 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: Jongseok Kim <ks77sj@xxxxxxxxx>
Subject: mm/z3fold.c: fix wrong handling of headless pages
During the processing of headless pages in z3fold_reclaim_page(), there
was a problem that the zhdr pointed to another page or a page was already
released in z3fold_free(). So, the wrong page is encoded in headless, or
test_bit does not work properly in z3fold_reclaim_page(). This patch
fixed these problems.
Link: http://lkml.kernel.org/r/1530853846-30215-1-git-send-email-ks77sj@xxxxxxxxx
Signed-off-by: Jongseok Kim <ks77sj@xxxxxxxxx>
Cc: Vitaly Wool <vitalywool@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/z3fold.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff -puN mm/z3fold.c~z3fold-fix-wrong-handling-of-headless-pages mm/z3fold.c
--- a/mm/z3fold.c~z3fold-fix-wrong-handling-of-headless-pages
+++ a/mm/z3fold.c
@@ -746,6 +746,9 @@ static void z3fold_free(struct z3fold_po
}
if (bud == HEADLESS) {
+ if (test_bit(UNDER_RECLAIM, &page->private))
+ return;
+
spin_lock(&pool->lock);
list_del(&page->lru);
spin_unlock(&pool->lock);
@@ -836,20 +839,20 @@ static int z3fold_reclaim_page(struct z3
}
list_for_each_prev(pos, &pool->lru) {
page = list_entry(pos, struct page, lru);
+ zhdr = page_address(page);
if (test_bit(PAGE_HEADLESS, &page->private))
/* candidate found */
break;
- zhdr = page_address(page);
if (!z3fold_page_trylock(zhdr))
continue; /* can't evict at this point */
kref_get(&zhdr->refcount);
list_del_init(&zhdr->buddy);
zhdr->cpu = -1;
- set_bit(UNDER_RECLAIM, &page->private);
break;
}
+ set_bit(UNDER_RECLAIM, &page->private);
list_del_init(&page->lru);
spin_unlock(&pool->lock);
@@ -898,6 +901,7 @@ next:
if (test_bit(PAGE_HEADLESS, &page->private)) {
if (ret == 0) {
free_z3fold_page(page);
+ atomic64_dec(&pool->pages_nr);
return 0;
}
spin_lock(&pool->lock);
_
Patches currently in -mm which might be from ks77sj@xxxxxxxxx are
z3fold-fix-wrong-handling-of-headless-pages.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
