From 686d550d222e8f83f6e709debbedf9d8ef77aec7 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 5 Sep 2012 00:20:33 +0000 Subject: [PATCH 1/1] mm/slab_common: Improve error handling in kmem_cache_create Instead of using s == NULL use an errorcode. This allows much more detailed diagnostics as to what went wrong. As we add more functionality from the slab allocators to the common kmem_cache_create() function we will also add more error conditions. Print the error code during the panic as well as in a warning if the module can handle failure. The API for kmem_cache_create() currently does not allow the returning of an error code. Return NULL but log the cause of the problem in the syslog. Reviewed-by: Glauber Costa Acked-by: David Rientjes Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slab_common.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 8cf8b49..fe8dc94 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -98,16 +98,36 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align unsigned long flags, void (*ctor)(void *)) { struct kmem_cache *s = NULL; + int err = 0; get_online_cpus(); mutex_lock(&slab_mutex); - if (kmem_cache_sanity_check(name, size) == 0) - s = __kmem_cache_create(name, size, align, flags, ctor); + + if (!kmem_cache_sanity_check(name, size) == 0) + goto out_locked; + + + s = __kmem_cache_create(name, size, align, flags, ctor); + if (!s) + err = -ENOSYS; /* Until __kmem_cache_create returns code */ + +out_locked: mutex_unlock(&slab_mutex); put_online_cpus(); - if (!s && (flags & SLAB_PANIC)) - panic("kmem_cache_create: Failed to create slab '%s'\n", name); + if (err) { + + if (flags & SLAB_PANIC) + panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", + name, err); + else { + printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", + name, err); + dump_stack(); + } + + return NULL; + } return s; } -- 2.7.4