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lru_cache: use atomic operations when accessing lc->flags, always

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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 <lars.ellenberg@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20221122134301.69258-2-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Lars Ellenberg 2022-11-22 14:42:58 +01:00 committed by Jens Axboe
parent d4b2e0d433
commit f2d03d8961
1 changed files with 2 additions and 2 deletions
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4
lib/lru_cache.c
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@ -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);
}