On 02/07/2016 10:10 PM, Vladimir Davydov wrote:
On Fri, Feb 05, 2016 at 08:16:52PM +0300, Dmitry Safonov wrote:
...
diff --git a/mm/slab.c b/mm/slab.c
index 6ecc697..41176dd 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2414,13 +2414,19 @@ int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate)
int __kmem_cache_shutdown(struct kmem_cache *cachep)
{
- int i;
- struct kmem_cache_node *n;
int rc = __kmem_cache_shrink(cachep, false);
if (rc)
return rc;
Nit:
int __kmem_cache_shutdown(struct kmem_cache *cachep)
{
- int rc = __kmem_cache_shrink(cachep, false);
-
- if (rc)
- return rc;
-
- return 0;
+ return __kmem_cache_shrink(cachep, false);
}
Will do
+ return 0;
+}
+
+void __kmem_cache_release(struct kmem_cache *cachep)
+{
+ int i;
+ struct kmem_cache_node *n;
+
free_percpu(cachep->cpu_cache);
/* NUMA: free the node structures */
@@ -2430,7 +2436,6 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
kfree(n);
cachep->node[i] = NULL;
}
- return 0;
}
/*
You seem to forget to replace __kmem_cache_shutdown with
__kmem_cache_release in __kmem_cache_create error path:
@@ -2168,7 +2168,7 @@ done:
err = setup_cpu_cache(cachep, gfp);
if (err) {
- __kmem_cache_shutdown(cachep);
+ __kmem_cache_release(cachep);
return err;
}
...
Yeah, thanks
diff --git a/mm/slub.c b/mm/slub.c
index 2e1355a..ce21ce2 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3173,11 +3173,12 @@ static void early_kmem_cache_node_alloc(int node)
__add_partial(n, page, DEACTIVATE_TO_HEAD);
}
-static void free_kmem_cache_nodes(struct kmem_cache *s)
+void __kmem_cache_release(struct kmem_cache *s)
{
int node;
struct kmem_cache_node *n;
+ free_percpu(s->cpu_slab);
That's rather nit-picking, but this kinda disrupts
init_kmem_cache_nodes/free_kmem_cache_nodes symmetry.
I'd leave free_kmem_cache_nodes alone and make
__kmem_cache_release call it along with free_percpu.
This would also reduce the patch footprint, because
the two hunks below wouldn't be needed.
Ok
for_each_kmem_cache_node(s, node, n) {
kmem_cache_free(kmem_cache_node, n);
s->node[node] = NULL;
@@ -3199,7 +3200,7 @@ static int init_kmem_cache_nodes(struct kmem_cache *s)
GFP_KERNEL, node);
if (!n) {
- free_kmem_cache_nodes(s);
+ __kmem_cache_release(s);
return 0;
}
@@ -3405,7 +3406,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags)
if (alloc_kmem_cache_cpus(s))
return 0;
- free_kmem_cache_nodes(s);
+ __kmem_cache_release(s);
error:
if (flags & SLAB_PANIC)
panic("Cannot create slab %s size=%lu realsize=%u "
@@ -3443,7 +3444,7 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
/*
* Attempt to free all partial slabs on a node.
- * This is called from kmem_cache_close(). We must be the last thread
+ * This is called from __kmem_cache_shutdown(). We must be the last thread
* using the cache and therefore we do not need to lock anymore.
Well, that's not true as we've found out - sysfs might still access the
cache in parallel. And alloc_calls_show -> list_locations does walk over
the kmem_cache_node->partial list, which we prune on shutdown.
I guess we should reintroduce locking for free_partial() in the scope of
this patch, partially reverting 69cb8e6b7c298.
I think, we can omit locking for !SLAB_SUPPORTS_SYSFS and reintroduce
for sysfs case. Will do
*/
static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
@@ -3456,7 +3457,7 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
discard_slab(s, page);
} else {
list_slab_objects(s, page,
- "Objects remaining in %s on kmem_cache_close()");
+ "Objects remaining in %s on __kmem_cache_shutdown()");
}
}
}
@@ -3464,7 +3465,7 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
/*
* Release all resources used by a slab cache.
*/
-static inline int kmem_cache_close(struct kmem_cache *s)
+int __kmem_cache_shutdown(struct kmem_cache *s)
{
int node;
struct kmem_cache_node *n;
@@ -3476,16 +3477,9 @@ static inline int kmem_cache_close(struct kmem_cache *s)
if (n->nr_partial || slabs_node(s, node))
return 1;
}
- free_percpu(s->cpu_slab);
- free_kmem_cache_nodes(s);
return 0;
}
-int __kmem_cache_shutdown(struct kmem_cache *s)
-{
- return kmem_cache_close(s);
-}
-
/********************************************************************
* Kmalloc subsystem
*******************************************************************/
@@ -3979,8 +3973,10 @@ int __kmem_cache_create(struct kmem_cache *s, unsigned long flags)
memcg_propagate_slab_attrs(s);
err = sysfs_slab_add(s);
- if (err)
- kmem_cache_close(s);
+ if (err) {
+ __kmem_cache_shutdown(s);
+ __kmem_cache_release(s);
+ }
No point calling __kmem_cache_shutdown on __kmem_cache_create error path
- the cache hasn't been used yet.
Oh, yes. Thanks for review.
Thanks,
Vladimir
--
Regards,
Dmitry Safonov
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