From f2d03d89615ef65b5dff3aae6581df0b5fcbaa3b Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 22 Nov 2022 14:42:58 +0100 Subject: [PATCH] lru_cache: use atomic operations when accessing lc->flags, always MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Or, depending on the way locking is implemented at the call sites, some updates could be lost (has not been observed). Signed-off-by: Lars Ellenberg Signed-off-by: Christoph Böhmwalder Link: https://lore.kernel.org/r/20221122134301.69258-2-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe --- lib/lru_cache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/lru_cache.c b/lib/lru_cache.c index dc35464..fec8993 100644 --- a/lib/lru_cache.c +++ b/lib/lru_cache.c @@ -364,7 +364,7 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsig struct lc_element *e; PARANOIA_ENTRY(); - if (lc->flags & LC_STARVING) { + if (test_bit(__LC_STARVING, &lc->flags)) { ++lc->starving; RETURN(NULL); } @@ -417,7 +417,7 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsig * the LRU element, we have to wait ... */ if (!lc_unused_element_available(lc)) { - __set_bit(__LC_STARVING, &lc->flags); + set_bit(__LC_STARVING, &lc->flags); RETURN(NULL); } -- 2.7.4