From: Shakeel Butt Date: Wed, 14 May 2025 18:41:55 +0000 (-0700) Subject: memcg: make count_memcg_events re-entrant safe against irqs X-Git-Tag: v6.16-rc1~92^2~8 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e52401e7247bb36cabba389ae32fb75a12a6e94b;p=thirdparty%2Flinux.git memcg: make count_memcg_events re-entrant safe against irqs Let's make count_memcg_events re-entrant safe against irqs. The only thing needed is to convert the usage of __this_cpu_add() to this_cpu_add(). In addition, with re-entrant safety, there is no need to disable irqs. Also add warnings for in_nmi() as it is not safe against nmi context. Link: https://lkml.kernel.org/r/20250514184158.3471331-5-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt Acked-by: Vlastimil Babka Cc: Alexei Starovoitov Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Cc: Sebastian Andrzej Siewior Signed-off-by: Andrew Morton --- diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 92861ff3c43fc..f7848f73f41c0 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -942,19 +942,8 @@ static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx, local_irq_restore(flags); } -void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, - unsigned long count); - -static inline void count_memcg_events(struct mem_cgroup *memcg, - enum vm_event_item idx, - unsigned long count) -{ - unsigned long flags; - - local_irq_save(flags); - __count_memcg_events(memcg, idx, count); - local_irq_restore(flags); -} +void count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, + unsigned long count); static inline void count_memcg_folio_events(struct folio *folio, enum vm_event_item idx, unsigned long nr) @@ -1418,12 +1407,6 @@ static inline void mod_lruvec_kmem_state(void *p, enum node_stat_item idx, } static inline void count_memcg_events(struct mem_cgroup *memcg, - enum vm_event_item idx, - unsigned long count) -{ -} - -static inline void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, unsigned long count) { diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c index 54c49cbfc968c..4b94731305b9f 100644 --- a/mm/memcontrol-v1.c +++ b/mm/memcontrol-v1.c @@ -512,9 +512,9 @@ static void memcg1_charge_statistics(struct mem_cgroup *memcg, int nr_pages) { /* pagein of a big page is an event. So, ignore page size */ if (nr_pages > 0) - __count_memcg_events(memcg, PGPGIN, 1); + count_memcg_events(memcg, PGPGIN, 1); else { - __count_memcg_events(memcg, PGPGOUT, 1); + count_memcg_events(memcg, PGPGOUT, 1); nr_pages = -nr_pages; /* for event */ } @@ -689,7 +689,7 @@ void memcg1_uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, unsigned long flags; local_irq_save(flags); - __count_memcg_events(memcg, PGPGOUT, pgpgout); + count_memcg_events(memcg, PGPGOUT, pgpgout); __this_cpu_add(memcg->events_percpu->nr_page_events, nr_memory); memcg1_check_events(memcg, nid); local_irq_restore(flags); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 25d5b198c8af2..0ef7db12605b4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -823,12 +823,12 @@ void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) } /** - * __count_memcg_events - account VM events in a cgroup + * count_memcg_events - account VM events in a cgroup * @memcg: the memory cgroup * @idx: the event item * @count: the number of events that occurred */ -void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, +void count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, unsigned long count) { int i = memcg_events_index(idx); @@ -842,7 +842,7 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, cpu = get_cpu(); - __this_cpu_add(memcg->vmstats_percpu->events[i], count); + this_cpu_add(memcg->vmstats_percpu->events[i], count); memcg_rstat_updated(memcg, count, cpu); trace_count_memcg_events(memcg, idx, count); diff --git a/mm/swap.c b/mm/swap.c index 77b2d59978734..4fc322f7111a9 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -309,7 +309,7 @@ static void lru_activate(struct lruvec *lruvec, struct folio *folio) trace_mm_lru_activate(folio); __count_vm_events(PGACTIVATE, nr_pages); - __count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE, nr_pages); + count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE, nr_pages); } #ifdef CONFIG_SMP @@ -581,7 +581,7 @@ static void lru_deactivate_file(struct lruvec *lruvec, struct folio *folio) if (active) { __count_vm_events(PGDEACTIVATE, nr_pages); - __count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, + count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_pages); } } @@ -599,7 +599,7 @@ static void lru_deactivate(struct lruvec *lruvec, struct folio *folio) lruvec_add_folio(lruvec, folio); __count_vm_events(PGDEACTIVATE, nr_pages); - __count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_pages); + count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_pages); } static void lru_lazyfree(struct lruvec *lruvec, struct folio *folio) @@ -625,7 +625,7 @@ static void lru_lazyfree(struct lruvec *lruvec, struct folio *folio) lruvec_add_folio(lruvec, folio); __count_vm_events(PGLAZYFREE, nr_pages); - __count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE, nr_pages); + count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE, nr_pages); } /* diff --git a/mm/vmscan.c b/mm/vmscan.c index 7d6d1ce3921e4..07c51fa034341 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2028,7 +2028,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, item = PGSCAN_KSWAPD + reclaimer_offset(sc); if (!cgroup_reclaim(sc)) __count_vm_events(item, nr_scanned); - __count_memcg_events(lruvec_memcg(lruvec), item, nr_scanned); + count_memcg_events(lruvec_memcg(lruvec), item, nr_scanned); __count_vm_events(PGSCAN_ANON + file, nr_scanned); spin_unlock_irq(&lruvec->lru_lock); @@ -2048,7 +2048,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, item = PGSTEAL_KSWAPD + reclaimer_offset(sc); if (!cgroup_reclaim(sc)) __count_vm_events(item, nr_reclaimed); - __count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed); + count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed); __count_vm_events(PGSTEAL_ANON + file, nr_reclaimed); spin_unlock_irq(&lruvec->lru_lock); @@ -2138,7 +2138,7 @@ static void shrink_active_list(unsigned long nr_to_scan, if (!cgroup_reclaim(sc)) __count_vm_events(PGREFILL, nr_scanned); - __count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned); + count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned); spin_unlock_irq(&lruvec->lru_lock); @@ -2195,7 +2195,7 @@ static void shrink_active_list(unsigned long nr_to_scan, nr_deactivate = move_folios_to_lru(lruvec, &l_inactive); __count_vm_events(PGDEACTIVATE, nr_deactivate); - __count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate); + count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate); __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); spin_unlock_irq(&lruvec->lru_lock); @@ -4612,8 +4612,8 @@ static int scan_folios(struct lruvec *lruvec, struct scan_control *sc, __count_vm_events(item, isolated); __count_vm_events(PGREFILL, sorted); } - __count_memcg_events(memcg, item, isolated); - __count_memcg_events(memcg, PGREFILL, sorted); + count_memcg_events(memcg, item, isolated); + count_memcg_events(memcg, PGREFILL, sorted); __count_vm_events(PGSCAN_ANON + type, isolated); trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, MAX_LRU_BATCH, scanned, skipped, isolated, @@ -4763,7 +4763,7 @@ retry: item = PGSTEAL_KSWAPD + reclaimer_offset(sc); if (!cgroup_reclaim(sc)) __count_vm_events(item, reclaimed); - __count_memcg_events(memcg, item, reclaimed); + count_memcg_events(memcg, item, reclaimed); __count_vm_events(PGSTEAL_ANON + type, reclaimed); spin_unlock_irq(&lruvec->lru_lock);