On 02/03/2016 12:44 PM, Vladimir Davydov wrote:
On Wed, Feb 03, 2016 at 10:52:13AM +0300, Dmitry Safonov wrote:
...
diff --git a/mm/slab_common.c b/mm/slab_common.c
index b50aef0..2bfc0b1 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -451,6 +451,8 @@ EXPORT_SYMBOL(kmem_cache_create);
static int shutdown_cache(struct kmem_cache *s,
struct list_head *release, bool *need_rcu_barrier)
{
+ sysfs_slab_remove(s);
+
shutdown_cache is called with slab_mutex held. slab_attr_store may take
the mutex. So placing sysfs_slab_remove here introduces a potential
deadlock.
if (__kmem_cache_shutdown(s) != 0)
return -EBUSY;
@@ -468,13 +470,8 @@ static void release_caches(struct list_head *release, bool need_rcu_barrier)
if (need_rcu_barrier)
rcu_barrier();
- list_for_each_entry_safe(s, s2, release, list) {
-#ifdef SLAB_SUPPORTS_SYSFS
- sysfs_slab_remove(s);
-#else
+ list_for_each_entry_safe(s, s2, release, list)
slab_kmem_cache_release(s);
-#endif
- }
}
#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
@@ -614,6 +611,7 @@ void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
list_for_each_entry_safe(s, s2, &slab_caches, list) {
if (is_root_cache(s) || s->memcg_params.memcg != memcg)
continue;
+
Please remove this hunk.
/*
* The cgroup is about to be freed and therefore has no charges
* left. Hence, all its caches must be empty by now.
diff --git a/mm/slub.c b/mm/slub.c
index 2e1355a..b6a68b7 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5296,11 +5296,6 @@ static void memcg_propagate_slab_attrs(struct kmem_cache *s)
#endif
}
-static void kmem_cache_release(struct kobject *k)
-{
- slab_kmem_cache_release(to_slab(k));
-}
-
static const struct sysfs_ops slab_sysfs_ops = {
.show = slab_attr_show,
.store = slab_attr_store,
@@ -5308,7 +5303,6 @@ static const struct sysfs_ops slab_sysfs_ops = {
static struct kobj_type slab_ktype = {
.sysfs_ops = &slab_sysfs_ops,
- .release = kmem_cache_release,
I surmise this will resurrect the bug that was fixed by 41a212859a4dd
("slub: use sysfs'es release mechanism for kmem_cache").
So, I move __kmem_cache_shutdown into slab_kmem_cache_release,
release list will still be collected under slab_mutex.
Seems like no other way to do this.
Will resend mended version.
Thanks,
Vladimir
--
Regards,
Dmitry Safonov
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