| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 019/217] mm/kmemleak.c: make cond_resched() rate-limiting more efficient | Date | Mon, 20 Sep 2021 18:40:40 +0200 |
| |
From: Andrew Morton <akpm@linux-foundation.org>
commit 13ab183d138f607d885e995d625e58d47678bf97 upstream.
Commit bde5f6bc68db ("kmemleak: add scheduling point to kmemleak_scan()") tries to rate-limit the frequency of cond_resched() calls, but does it in a way which might incur an expensive division operation in the inner loop. Simplify this.
Fixes: bde5f6bc68db5 ("kmemleak: add scheduling point to kmemleak_scan()") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Yisheng Xie <xieyisheng1@huawei.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1520,7 +1520,7 @@ static void kmemleak_scan(void) if (page_count(page) == 0) continue; scan_block(page, page + 1, NULL); - if (!(pfn % (MAX_SCAN_SIZE / sizeof(*page)))) + if (!(pfn & 63)) cond_resched(); } }
|