diff options
| author | Shakeel Butt <shakeel.butt@linux.dev> | 2025-11-07 15:40:41 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-20 13:43:59 -0800 |
| commit | bc8e51c05ad50a5a0b02114d3cc94d151a332595 (patch) | |
| tree | f4fb70d09c8fd6a0ada55921d0a7b58d1c065cb8 | |
| parent | 05be0287955970b043a0742e85b6c285dea4f286 (diff) | |
| download | tip-bc8e51c05ad50a5a0b02114d3cc94d151a332595.tar.gz | |
mm: memcg: dump memcg protection info on oom or alloc failures
Currently kernel dumps memory state on oom and allocation failures. One
of the question usually raised on those dumps is why the kernel has not
reclaimed the reclaimable memory instead of triggering oom. One potential
reason is the usage of memory protection provided by memcg. So, let's
also dump the memory protected by the memcg in such reports to ease the
debugging.
Link: https://lkml.kernel.org/r/20251107234041.3632644-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/memcontrol.h | 5 | ||||
| -rw-r--r-- | mm/memcontrol.c | 13 | ||||
| -rw-r--r-- | mm/oom_kill.c | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 1 |
4 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 8c0f15e5978fa5..966f7c1a0128f3 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1764,6 +1764,7 @@ static inline void count_objcg_events(struct obj_cgroup *objcg, bool mem_cgroup_node_allowed(struct mem_cgroup *memcg, int nid); +void mem_cgroup_show_protected_memory(struct mem_cgroup *memcg); #else static inline bool mem_cgroup_kmem_disabled(void) { @@ -1830,6 +1831,10 @@ static inline bool mem_cgroup_node_allowed(struct mem_cgroup *memcg, int nid) { return true; } + +static inline void mem_cgroup_show_protected_memory(struct mem_cgroup *memcg) +{ +} #endif /* CONFIG_MEMCG */ #if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 025da46d9959fd..bfc986da3289a7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5635,3 +5635,16 @@ bool mem_cgroup_node_allowed(struct mem_cgroup *memcg, int nid) { return memcg ? cpuset_node_allowed(memcg->css.cgroup, nid) : true; } + +void mem_cgroup_show_protected_memory(struct mem_cgroup *memcg) +{ + if (mem_cgroup_disabled() || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return; + + if (!memcg) + memcg = root_mem_cgroup; + + pr_warn("Memory cgroup min protection %lukB -- low protection %lukB", + K(atomic_long_read(&memcg->memory.children_min_usage)*PAGE_SIZE), + K(atomic_long_read(&memcg->memory.children_low_usage)*PAGE_SIZE)); +} diff --git a/mm/oom_kill.c b/mm/oom_kill.c index c145b0feecc1f2..5eb11fbba70432 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -472,6 +472,7 @@ static void dump_header(struct oom_control *oc) if (should_dump_unreclaim_slab()) dump_unreclaimable_slab(); } + mem_cgroup_show_protected_memory(oc->memcg); if (sysctl_oom_dump_tasks) dump_tasks(oc); } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e4efda1158b250..26be5734253f35 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3977,6 +3977,7 @@ static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask) filter &= ~SHOW_MEM_FILTER_NODES; __show_mem(filter, nodemask, gfp_zone(gfp_mask)); + mem_cgroup_show_protected_memory(NULL); } void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) |