diff --git a/mm/vmscan.c b/mm/vmscan.c index 078cf920208..b0cd81c32de 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -201,13 +201,25 @@ static int shrink_slab(unsigned long scanned, gfp_t gfp_mask, list_for_each_entry(shrinker, &shrinker_list, list) { unsigned long long delta; unsigned long total_scan; + unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask); delta = (4 * scanned) / shrinker->seeks; - delta *= (*shrinker->shrinker)(0, gfp_mask); + delta *= max_pass; do_div(delta, lru_pages + 1); shrinker->nr += delta; - if (shrinker->nr < 0) - shrinker->nr = LONG_MAX; /* It wrapped! */ + if (shrinker->nr < 0) { + printk(KERN_ERR "%s: nr=%ld\n", + __FUNCTION__, shrinker->nr); + shrinker->nr = max_pass; + } + + /* + * Avoid risking looping forever due to too large nr value: + * never try to free more than twice the estimate number of + * freeable entries. + */ + if (shrinker->nr > max_pass * 2) + shrinker->nr = max_pass * 2; total_scan = shrinker->nr; shrinker->nr = 0;