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-rw-r--r--mm/oom_kill.c27
-rw-r--r--mm/slab.h8
-rw-r--r--mm/slab_common.c34
3 files changed, 67 insertions, 2 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index dee0f75c3013..3023919970f7 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -44,6 +44,7 @@
#include <asm/tlb.h>
#include "internal.h"
+#include "slab.h"
#define CREATE_TRACE_POINTS
#include <trace/events/oom.h>
@@ -161,6 +162,25 @@ static bool oom_unkillable_task(struct task_struct *p,
return false;
}
+/*
+ * Print out unreclaimble slabs info when unreclaimable slabs amount is greater
+ * than all user memory (LRU pages)
+ */
+static bool is_dump_unreclaim_slabs(void)
+{
+ unsigned long nr_lru;
+
+ nr_lru = global_node_page_state(NR_ACTIVE_ANON) +
+ global_node_page_state(NR_INACTIVE_ANON) +
+ global_node_page_state(NR_ACTIVE_FILE) +
+ global_node_page_state(NR_INACTIVE_FILE) +
+ global_node_page_state(NR_ISOLATED_ANON) +
+ global_node_page_state(NR_ISOLATED_FILE) +
+ global_node_page_state(NR_UNEVICTABLE);
+
+ return (global_node_page_state(NR_SLAB_UNRECLAIMABLE) > nr_lru);
+}
+
/**
* oom_badness - heuristic function to determine which candidate task to kill
* @p: task struct of which task we should calculate
@@ -420,10 +440,13 @@ static void dump_header(struct oom_control *oc, struct task_struct *p)
cpuset_print_current_mems_allowed();
dump_stack();
- if (oc->memcg)
+ if (is_memcg_oom(oc))
mem_cgroup_print_oom_info(oc->memcg, p);
- else
+ else {
show_mem(SHOW_MEM_FILTER_NODES, oc->nodemask);
+ if (is_dump_unreclaim_slabs())
+ dump_unreclaimable_slab();
+ }
if (sysctl_oom_dump_tasks)
dump_tasks(oc->memcg, oc->nodemask);
}
diff --git a/mm/slab.h b/mm/slab.h
index 86d7c7d860f9..45c586cefc11 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -506,6 +506,14 @@ void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
void memcg_slab_stop(struct seq_file *m, void *p);
int memcg_slab_show(struct seq_file *m, void *p);
+#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
+void dump_unreclaimable_slab(void);
+#else
+static inline void dump_unreclaimable_slab(void)
+{
+}
+#endif
+
void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
#ifdef CONFIG_SLAB_FREELIST_RANDOM
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 9357353bcb64..8f7f9f75d7ea 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1280,6 +1280,40 @@ static int slab_show(struct seq_file *m, void *p)
return 0;
}
+void dump_unreclaimable_slab(void)
+{
+ struct kmem_cache *s, *s2;
+ struct slabinfo sinfo;
+
+ /*
+ * Here acquiring slab_mutex is risky since we don't prefer to get
+ * sleep in oom path. But, without mutex hold, it may introduce a
+ * risk of crash.
+ * Use mutex_trylock to protect the list traverse, dump nothing
+ * without acquiring the mutex.
+ */
+ if (!mutex_trylock(&slab_mutex)) {
+ pr_warn("excessive unreclaimable slab but cannot dump stats\n");
+ return;
+ }
+
+ pr_info("Unreclaimable slab info:\n");
+ pr_info("Name Used Total\n");
+
+ list_for_each_entry_safe(s, s2, &slab_caches, list) {
+ if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT))
+ continue;
+
+ get_slabinfo(s, &sinfo);
+
+ if (sinfo.num_objs > 0)
+ pr_info("%-17s %10luKB %10luKB\n", cache_name(s),
+ (sinfo.active_objs * s->size) / 1024,
+ (sinfo.num_objs * s->size) / 1024);
+ }
+ mutex_unlock(&slab_mutex);
+}
+
#if defined(CONFIG_MEMCG)
void *memcg_slab_start(struct seq_file *m, loff_t *pos)
{