Prevents deadlock situation between
kmem_cache_create()/kmem_cache_destory(), and kmem_cache_create() /cpu
hotplug. The locking order probably got moved over time.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
+ /*
+ * Prevent CPUs from coming and going.
+ * lock_cpu_hotplug() nests outside cache_chain_mutex
+ */
+ lock_cpu_hotplug();
+
mutex_lock(&cache_chain_mutex);
list_for_each(p, &cache_chain) {
mutex_lock(&cache_chain_mutex);
list_for_each(p, &cache_chain) {
cachep->dtor = dtor;
cachep->name = name;
cachep->dtor = dtor;
cachep->name = name;
- /* Don't let CPUs to come and go */
- lock_cpu_hotplug();
if (g_cpucache_up == FULL) {
enable_cpucache(cachep);
if (g_cpucache_up == FULL) {
enable_cpucache(cachep);
/* cache setup completed, link it into the list */
list_add(&cachep->next, &cache_chain);
/* cache setup completed, link it into the list */
list_add(&cachep->next, &cache_chain);
oops:
if (!cachep && (flags & SLAB_PANIC))
panic("kmem_cache_create(): failed to create slab `%s'\n",
name);
mutex_unlock(&cache_chain_mutex);
oops:
if (!cachep && (flags & SLAB_PANIC))
panic("kmem_cache_create(): failed to create slab `%s'\n",
name);
mutex_unlock(&cache_chain_mutex);
return cachep;
}
EXPORT_SYMBOL(kmem_cache_create);
return cachep;
}
EXPORT_SYMBOL(kmem_cache_create);