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From: David Rientjes <rientjes@google.com>
To: Christoph Lameter <cl@linux.com>
Cc: Glauber Costa <glommer@parallels.com>,
	linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
	linux-mm@kvack.org, Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [PATCH v2] slab+slob: dup name string
Date: Wed, 23 May 2012 18:01:51 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1205231759460.28167@chino.kir.corp.google.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1205230849410.29893@router.home>

On Wed, 23 May 2012, Christoph Lameter wrote:

> > No, it's not, there's no reason to prevent caches created before
> > g_cpucache_up <= EARLY to be destroyed because it makes a patch easier to
> > implement and then leave that little gotcha as an undocumented treasure
> > for someone to find when they try it later on.
> 
> g_cpucache_up <= EARLY is slab bootstrap code and the system is in a
> pretty fragile state. Plus the the kmalloc logic *depends* on these
> caches being present. Removing those is not a good idea. The other caches
> that are created at that point are needed to create more caches.
> 
> There is no reason to remove these caches.
> 

Yes, we know that we don't want to remove the caches that are currently 
created in kmem_cache_init(), it would be a pretty stupid thing to do.  
I'm talking about the possibility of creating additional caches while 
g_cpucache_up <= EARLY in the future and then finding that you can't 
destroy them because of this string allocation.  I don't think it's too 
difficult to statically allocate space for these names and then test for 
it before doing kfree() in kmem_cache_destroy(), it's not performance 
critical.

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      reply	other threads:[~2012-05-24  1:01 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-22  9:51 Glauber Costa
2012-05-22 13:58 ` Christoph Lameter
2012-05-22 15:27   ` Glauber Costa
2012-05-22 17:18     ` Christoph Lameter
2012-05-23  3:55   ` David Rientjes
2012-05-23  9:25     ` Glauber Costa
2012-05-23 13:53     ` Christoph Lameter
2012-05-24  1:01       ` David Rientjes [this message]

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