[PATCH] mm: memcontrol: switch to rstat fix
From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2021-03-15 23:41:58
Also in:
linux-mm, lkml
Subsystem:
control group - memory resource controller (memcg), memory management, the rest · Maintainers:
Johannes Weiner, Michal Hocko, Roman Gushchin, Shakeel Butt, Andrew Morton, Linus Torvalds
Fix a sleep in atomic section problem: wb_writeback() takes a spinlock and calls wb_over_bg_thresh() -> mem_cgroup_wb_stats, but the regular rstat flushing function called from in there does lockbreaking and may sleep. Switch to the atomic variant, cgroup_rstat_irqsafe(). To be consistent with other memcg flush calls, but without adding another memcg wrapper, inline and drop memcg_flush_vmstats() instead. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> --- mm/memcontrol.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f7fb12d3c2fc..9091913ec877 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c@@ -757,11 +757,6 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) return mz; } -static void memcg_flush_vmstats(struct mem_cgroup *memcg) -{ - cgroup_rstat_flush(memcg->css.cgroup); -} - /** * __mod_memcg_state - update cgroup memory statistics * @memcg: the memory cgroup
@@ -1572,7 +1567,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg) * * Current memory state: */ - memcg_flush_vmstats(memcg); + cgroup_rstat_flush(memcg->css.cgroup); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { u64 size;
@@ -3523,7 +3518,7 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) unsigned long val; if (mem_cgroup_is_root(memcg)) { - memcg_flush_vmstats(memcg); + cgroup_rstat_flush(memcg->css.cgroup); val = memcg_page_state(memcg, NR_FILE_PAGES) + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap)
@@ -3925,7 +3920,7 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) int nid; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - memcg_flush_vmstats(memcg); + cgroup_rstat_flush(memcg->css.cgroup); for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { seq_printf(m, "%s=%lu", stat->name,
@@ -3997,7 +3992,7 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - memcg_flush_vmstats(memcg); + cgroup_rstat_flush(memcg->css.cgroup); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { unsigned long nr;
@@ -4500,7 +4495,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - memcg_flush_vmstats(memcg); + cgroup_rstat_flush_irqsafe(memcg->css.cgroup); *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); *pwriteback = memcg_page_state(memcg, NR_WRITEBACK);
--
2.30.1