diff --git a/include/linux/swap.h b/include/linux/swap.h index bd450023b9a4..e685e93ba354 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -354,7 +354,8 @@ static inline swp_entry_t page_swap_entry(struct page *page) } /* linux/mm/workingset.c */ -bool workingset_test_recent(void *shadow, bool file, bool *workingset); +bool workingset_test_recent(void *shadow, bool file, bool *workingset, + bool flush); void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg); void workingset_refault(struct folio *folio, void *shadow); diff --git a/mm/filemap.c b/mm/filemap.c index fedefb10d947..298485d4b992 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -4248,6 +4248,9 @@ static void filemap_cachestat(struct address_space *mapping, XA_STATE(xas, &mapping->i_pages, first_index); struct folio *folio; + /* Flush stats (and potentially sleep) outside the RCU read section. */ + mem_cgroup_flush_stats_ratelimited(NULL); + rcu_read_lock(); xas_for_each(&xas, folio, last_index) { int order; @@ -4311,7 +4314,7 @@ static void filemap_cachestat(struct address_space *mapping, goto resched; } #endif - if (workingset_test_recent(shadow, true, &workingset)) + if (workingset_test_recent(shadow, true, &workingset, false)) cs->nr_recently_evicted += nr_pages; goto resched; diff --git a/mm/workingset.c b/mm/workingset.c index c22adb93622a..a2b28e356e68 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -412,10 +412,12 @@ void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg) * @file: whether the corresponding folio is from the file lru. * @workingset: where the workingset value unpacked from shadow should * be stored. + * @flush: whether to flush cgroup rstat. * * Return: true if the shadow is for a recently evicted folio; false otherwise. */ -bool workingset_test_recent(void *shadow, bool file, bool *workingset) +bool workingset_test_recent(void *shadow, bool file, bool *workingset, + bool flush) { struct mem_cgroup *eviction_memcg; struct lruvec *eviction_lruvec; @@ -467,10 +469,16 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset) /* * Flush stats (and potentially sleep) outside the RCU read section. + * + * Note that workingset_test_recent() itself might be called in RCU read + * section (for e.g, in cachestat) - these callers need to skip flushing + * stats (via the flush argument). + * * XXX: With per-memcg flushing and thresholding, is ratelimiting * still needed here? */ - mem_cgroup_flush_stats_ratelimited(eviction_memcg); + if (flush) + mem_cgroup_flush_stats_ratelimited(eviction_memcg); eviction_lruvec = mem_cgroup_lruvec(eviction_memcg, pgdat); refault = atomic_long_read(&eviction_lruvec->nonresident_age); @@ -558,7 +566,7 @@ void workingset_refault(struct folio *folio, void *shadow) mod_lruvec_state(lruvec, WORKINGSET_REFAULT_BASE + file, nr); - if (!workingset_test_recent(shadow, file, &workingset)) + if (!workingset_test_recent(shadow, file, &workingset, true)) return; folio_set_active(folio);