On Thu, 21 Sep 2017, Yang Shi wrote:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 99736e0..173c423 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -43,6 +43,7 @@
#include <asm/tlb.h>
#include "internal.h"
+#include "slab.h"
#define CREATE_TRACE_POINTS
#include <trace/events/oom.h>
@@ -427,6 +428,14 @@ static void dump_header(struct oom_control *oc, struct task_struct *p)
dump_tasks(oc->memcg, oc->nodemask);
}
+static void dump_header_with_slabinfo(struct oom_control *oc, struct task_struct *p)
+{
+ dump_header(oc, p);
+
+ if (IS_ENABLED(CONFIG_SLABINFO))
+ show_unreclaimable_slab();
+}
+
/*
* Number of OOM victims in flight
*/
I don't think we need a new function for this. Where you want to dump
unreclaimable slab before panic, just call a new dump_unreclaimable_slab()
function that gets declared in slab.h that is a no-op when CONFIG_SLABINFO
is disabled. We just want to do
dump_header(...);
dump_unreclaimable_slab(...);
panic(...);
diff --git a/mm/slab.c b/mm/slab.c
index 04dec48..4f4971c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4132,6 +4132,7 @@ void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
sinfo->shared = cachep->shared;
sinfo->objects_per_slab = cachep->num;
sinfo->cache_order = cachep->gfporder;
+ sinfo->reclaim = is_reclaimable(cachep);
We don't need a new field, we already have cachep->flags accessible.
}
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep)
diff --git a/mm/slab.h b/mm/slab.h
index 0733628..2f1ebce 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -186,6 +186,7 @@ struct slabinfo {
unsigned int shared;
unsigned int objects_per_slab;
unsigned int cache_order;
+ unsigned int reclaim;
Not needed.
};
void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
@@ -352,6 +353,11 @@ static inline void memcg_link_cache(struct kmem_cache *s)
#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
+static inline bool is_reclaimable(struct kmem_cache *s)
+{
+ return (s->flags & SLAB_RECLAIM_ACCOUNT) ? true : false;
+}
+
I don't think we need this.
static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
{
struct kmem_cache *cachep;
@@ -504,6 +510,7 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
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);
+void show_unreclaimable_slab(void);
void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 904a83b..f2c6200 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -35,6 +35,8 @@
static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
slab_caches_to_rcu_destroy_workfn);
+#define K(x) ((x)/1024)
+
I don't think we need this.
/*
* Set of flags that will prevent slab merging
*/
@@ -1272,6 +1274,35 @@ static int slab_show(struct seq_file *m, void *p)
return 0;
}
+void show_unreclaimable_slab()
void show_unreclaimable_slab(void)
+{
+ struct kmem_cache *s = NULL;
No initialization needed.
+ struct slabinfo sinfo;
+
+ memset(&sinfo, 0, sizeof(sinfo));
+
+ printk("Unreclaimable slab info:\n");
+ printk("Name Used Total\n");
+
+ /*
+ * Here acquiring slab_mutex is unnecessary since we don't prefer to
+ * get sleep in oom path right before kernel panic, and avoid race condition.
+ * Since it is already oom, so there should be not any big allocation
+ * which could change the statistics significantly.
+ */
+ list_for_each_entry(s, &slab_caches, list) {
+ if (!is_root_cache(s))
+ continue;
+
We need to do the memset() here.
+ get_slabinfo(s, &sinfo);
+
+ if (!is_reclaimable(s) && sinfo.num_objs > 0)
+ printk("%-17s %10luKB %10luKB\n", cache_name(s), K(sinfo.active_objs * s->size), K(sinfo.num_objs * s->size));
I think you can just check for SLAB_RECLAIM_ACCOUNT here.
Everything in this function should be pr_info().
+ }
+}
+EXPORT_SYMBOL(show_unreclaimable_slab);
+#undef K
+
#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
void *memcg_slab_start(struct seq_file *m, loff_t *pos)
{
diff --git a/mm/slub.c b/mm/slub.c
index 163352c..5c17c0a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5872,6 +5872,7 @@ void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
sinfo->num_slabs = nr_slabs;
sinfo->objects_per_slab = oo_objects(s->oo);
sinfo->cache_order = oo_order(s->oo);
+ sinfo->reclaim = is_reclaimable(s);
Not needed.
}
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s)
