From: Christoph Lameter <cl@linux.com>
To: Glauber Costa <glommer@parallels.com>
Cc: Pekka Enberg <penberg@kernel.org>,
linux-mm@kvack.org, David Rientjes <rientjes@google.com>,
Joonsoo Kim <js1304@gmail.com>
Subject: Common [04/19] Improve error handling in kmem_cache_create
Date: Thu, 02 Aug 2012 15:15:10 -0500 [thread overview]
Message-ID: <20120802201532.623330251@linux.com> (raw)
In-Reply-To: 20120802201506.266817615@linux.com
[-- Attachment #1: error_handling_in_kmem_cache_create --]
[-- Type: text/plain, Size: 2356 bytes --]
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.
Signed-off-by: Christoph Lameter <cl@linux.com>
Index: linux-2.6/mm/slab_common.c
===================================================================
--- linux-2.6.orig/mm/slab_common.c 2012-08-02 14:00:41.547674458 -0500
+++ linux-2.6/mm/slab_common.c 2012-08-02 14:21:07.061676525 -0500
@@ -51,13 +51,13 @@
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;
#ifdef CONFIG_DEBUG_VM
if (!name || in_interrupt() || size < sizeof(void *) ||
size > KMALLOC_MAX_SIZE) {
- printk(KERN_ERR "kmem_cache_create(%s) integrity check"
- " failed\n", name);
+ err = -EINVAL;
goto out;
}
#endif
@@ -84,11 +84,7 @@
}
if (!strcmp(s->name, name)) {
- printk(KERN_ERR "kmem_cache_create(%s): Cache name"
- " already exists.\n",
- name);
- dump_stack();
- s = NULL;
+ err = -EEXIST;
goto out_locked;
}
}
@@ -97,6 +93,8 @@
#endif
s = __kmem_cache_create(name, size, align, flags, ctor);
+ if (!s)
+ err = -ENOSYS; /* Until __kmem_cache_create returns code */
#ifdef CONFIG_DEBUG_VM
out_locked:
@@ -107,8 +105,19 @@
#ifdef CONFIG_DEBUG_VM
out:
#endif
- 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;
}
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2012-08-02 20:15 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-02 20:15 Common [00/19] Sl[auo]b: Common code rework V9 Christoph Lameter
2012-08-02 20:15 ` Common [01/19] slub: Add debugging to verify correct cache use on kmem_cache_free() Christoph Lameter
2012-08-02 20:37 ` David Rientjes
2012-08-02 20:42 ` Christoph Lameter
2012-08-02 20:47 ` David Rientjes
2012-08-03 13:45 ` Christoph Lameter
2012-08-02 20:15 ` Common [02/19] slub: Use kmem_cache for the kmem_cache structure Christoph Lameter
2012-08-02 20:52 ` David Rientjes
2012-08-03 14:07 ` Christoph Lameter
2012-08-03 13:20 ` Glauber Costa
2012-08-03 13:52 ` Christoph Lameter
2012-08-03 13:53 ` Glauber Costa
2012-08-03 14:02 ` Christoph Lameter
2012-08-02 20:15 ` Common [03/19] Rename oops label Christoph Lameter
2012-08-02 20:45 ` David Rientjes
2012-08-02 20:15 ` Christoph Lameter [this message]
2012-08-02 20:58 ` Common [04/19] Improve error handling in kmem_cache_create David Rientjes
2012-08-02 20:15 ` Common [05/19] Move list_add() to slab_common.c Christoph Lameter
2012-08-02 21:18 ` David Rientjes
2012-08-02 20:15 ` Common [06/19] Extract a common function for kmem_cache_destroy Christoph Lameter
2012-08-02 20:15 ` Common [07/19] Always use the name "kmem_cache" for the slab cache with the kmem_cache structure Christoph Lameter
2012-08-02 20:15 ` Common [08/19] Move freeing of kmem_cache structure to common code Christoph Lameter
2012-08-02 20:15 ` Common [09/19] Get rid of __kmem_cache_destroy Christoph Lameter
2012-08-02 20:15 ` Common [10/19] Move duping of slab name to slab_common.c Christoph Lameter
2012-08-02 20:15 ` Common [11/19] Do slab aliasing call from common code Christoph Lameter
2012-08-02 20:15 ` Common [12/19] Move sysfs_slab_add to common Christoph Lameter
2012-08-02 20:15 ` Common [13/19] slub: Use a statically allocated kmem_cache boot structure for bootstrap Christoph Lameter
2012-08-02 20:15 ` Common [14/19] slub: Introduce function for opening boot caches Christoph Lameter
2012-08-02 20:15 ` Common [15/19] create common create_kmalloc_cache() Christoph Lameter
2012-08-02 20:15 ` Common [16/19] Move kmem_cache allocations into common code Christoph Lameter
2012-08-02 20:15 ` Common [17/19] Shrink __kmem_cache_create() parameter lists Christoph Lameter
2012-08-02 20:15 ` Common [18/19] Move kmem_cache refcounting to common code Christoph Lameter
2012-08-02 20:15 ` Common [19/19] Common alignment code Christoph Lameter
2012-08-03 13:09 ` Common [00/19] Sl[auo]b: Common code rework V9 Glauber Costa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120802201532.623330251@linux.com \
--to=cl@linux.com \
--cc=glommer@parallels.com \
--cc=js1304@gmail.com \
--cc=linux-mm@kvack.org \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).