From: Christoph Lameter <cl@linux.com>
To: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>,
David Rientjes <rientjes@google.com>,
Glauber Costa <glommer@parallels.com>,
linux-mm@kvack.org
Subject: C12 [03/19] Improve error handling in kmem_cache_create
Date: Mon, 20 Aug 2012 20:50:35 +0000 [thread overview]
Message-ID: <0000013945cd242a-dc004a79-a63a-4758-a4d2-974b36030f18-000000@email.amazonses.com> (raw)
In-Reply-To: <20120820204021.494276880@linux.com>
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.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
---
mm/slab_common.c | 28 +++++++++++++++++++++++-----
1 file changed, 23 insertions(+), 5 deletions(-)
Index: linux/mm/slab_common.c
===================================================================
--- linux.orig/mm/slab_common.c 2012-08-17 14:51:51.000000000 -0500
+++ linux/mm/slab_common.c 2012-08-17 14:53:03.741358408 -0500
@@ -97,17 +97,37 @@ static inline int kmem_cache_sanity_chec
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;
+ struct kmem_cache *s;
+ 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;
}
--
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next prev parent reply other threads:[~2012-08-20 20:50 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120820204021.494276880@linux.com>
2012-08-20 20:47 ` C12 [01/19] slub: Add debugging to verify correct cache use on kmem_cache_free() Christoph Lameter
2012-08-20 20:50 ` C12 [05/19] Extract a common function for kmem_cache_destroy Christoph Lameter
2012-08-20 20:50 ` Christoph Lameter [this message]
2012-08-20 20:50 ` C12 [04/19] Move list_add() to slab_common.c Christoph Lameter
2012-08-20 20:50 ` C12 [01/19] slub: Add debugging to verify correct cache use on kmem_cache_free() Christoph Lameter
2012-08-20 20:50 ` C12 [02/19] slub: Use kmem_cache for the kmem_cache structure Christoph Lameter
2012-08-20 20:50 ` C12 [11/19] Move sysfs_slab_add to common Christoph Lameter
2012-08-20 20:50 ` C12 [06/19] Always use the name "kmem_cache" for the slab cache with the kmem_cache structure Christoph Lameter
2012-08-20 20:50 ` C12 [07/19] Move freeing of kmem_cache structure to common code Christoph Lameter
2012-08-20 20:50 ` C12 [12/19] Move kmem_cache allocations into " Christoph Lameter
2012-08-21 11:55 ` Glauber Costa
2012-08-21 20:58 ` Christoph Lameter
2012-08-22 8:42 ` Glauber Costa
2012-08-22 15:25 ` Christoph Lameter
2012-08-23 7:43 ` Glauber Costa
2012-08-23 13:49 ` Christoph Lameter
2012-08-23 13:57 ` Glauber Costa
2012-08-23 14:31 ` Christoph Lameter
2012-08-20 20:50 ` C12 [09/19] Move duping of slab name to slab_common.c Christoph Lameter
2012-08-20 20:50 ` C12 [10/19] Do slab aliasing call from common code Christoph Lameter
2012-08-20 20:50 ` C12 [13/19] Shrink __kmem_cache_create() parameter lists Christoph Lameter
2012-08-20 20:50 ` C12 [08/19] Get rid of __kmem_cache_destroy Christoph Lameter
2012-08-20 20:50 ` C12 [17/19] slub: Use a statically allocated kmem_cache boot structure for bootstrap Christoph Lameter
2012-08-20 20:50 ` C12 [16/19] Create common functions for boot slab creation Christoph Lameter
2012-08-22 9:26 ` Glauber Costa
2012-08-22 15:35 ` Christoph Lameter
2012-08-23 8:09 ` Glauber Costa
2012-08-23 13:58 ` Christoph Lameter
2012-08-20 20:50 ` C12 [14/19] Move kmem_cache refcounting to common code Christoph Lameter
2012-08-20 21:01 ` C12 [15/19] slab: Simplify bootstrap Christoph Lameter
2012-08-20 21:01 ` C12 [19/19] Common alignment code Christoph Lameter
2012-08-20 21:01 ` C12 [18/19] slab: Use the new create_boot_cache function to simplify bootstrap Christoph Lameter
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