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authorWaiman Long <longman@redhat.com>2023-08-25 12:49:47 -0400
committerAndrew Morton <akpm@linux-foundation.org>2023-09-02 15:17:34 -0700
commite68d343d2720779362cb7160cb7f4bd24979b2b4 (patch)
treef5f56525ff09ad3e80f5e2463ab9195b3a1859f1
parentf945116e4e191cd543ecd56d9f13e6331494847c (diff)
mm/kmemleak: move up cond_resched() call in page scanning loop
Commit bde5f6bc68db ("kmemleak: add scheduling point to kmemleak_scan()") added a cond_resched() call to the struct page scanning loop to prevent soft lockup from happening. However, soft lockup can still happen in that loop in some corner cases when the pages that satisfy the "!(pfn & 63)" check are skipped for some reasons. Fix this corner case by moving up the cond_resched() check so that it will be called every 64 pages unconditionally. Link: https://lkml.kernel.org/r/20230825164947.1317981-1-longman@redhat.com Fixes: bde5f6bc68db ("kmemleak: add scheduling point to kmemleak_scan()") Signed-off-by: Waiman Long <longman@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yisheng Xie <xieyisheng1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/kmemleak.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 2918150e31bd..54c2c90d3abc 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1584,6 +1584,9 @@ static void kmemleak_scan(void)
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
struct page *page = pfn_to_online_page(pfn);
+ if (!(pfn & 63))
+ cond_resched();
+
if (!page)
continue;
@@ -1594,8 +1597,6 @@ static void kmemleak_scan(void)
if (page_count(page) == 0)
continue;
scan_block(page, page + 1, NULL);
- if (!(pfn & 63))
- cond_resched();
}
}
put_online_mems();