From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx101.postini.com [74.125.245.101]) by kanga.kvack.org (Postfix) with SMTP id B3A8A6B004D for ; Tue, 22 May 2012 03:25:51 -0400 (EDT) Message-ID: <4FBB3F04.7040207@parallels.com> Date: Tue, 22 May 2012 11:23:48 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH] slab+slob: dup name string References: <1337613539-29108-1-git-send-email-glommer@parallels.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Christoph Lameter , Pekka Enberg On 05/22/2012 07:22 AM, David Rientjes wrote: > On Mon, 21 May 2012, Glauber Costa wrote: > >> diff --git a/mm/slab.c b/mm/slab.c >> index e901a36..cabd217 100644 >> --- a/mm/slab.c >> +++ b/mm/slab.c >> @@ -2118,6 +2118,7 @@ static void __kmem_cache_destroy(struct kmem_cache *cachep) >> kfree(l3); >> } >> } >> + kfree(cachep->name); >> kmem_cache_free(&cache_cache, cachep); >> } >> >> @@ -2526,9 +2527,14 @@ kmem_cache_create (const char *name, size_t size, size_t align, >> BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); >> } >> cachep->ctor = ctor; >> - cachep->name = name; >> >> - if (setup_cpu_cache(cachep, gfp)) { >> + /* Can't do strdup while kmalloc is not up */ >> + if (g_cpucache_up> EARLY) >> + cachep->name = kstrdup(name, GFP_KERNEL); >> + else >> + cachep->name = name; >> + >> + if (!cachep->name || setup_cpu_cache(cachep, gfp)) { >> __kmem_cache_destroy(cachep); >> cachep = NULL; >> goto oops; > > This doesn't work if you kmem_cache_destroy() a cache that was created > when g_cpucache_cpu<= EARLY, the kfree() will explode. That never > happens for any existing cache created in kmem_cache_init(), but this > would introduce the first roadblock in doing so. So you'll need some > magic to determine whether the cache was allocated statically and suppress > the kfree() in such a case. Suggestions on how to do it other than using a flag? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org