Date: Fri, 23 Feb 2007 21:54:39 -0800 (PST)
Message-Id: <20070223.215439.92580943.davem@davemloft.net>
To: clameter@engr.sgi.com
Cc: kamezawa.hiroyu@jp.fujitsu.com, andi@firstfloor.org,
       akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
       linux-mm@kvack.org
Subject: Re: SLUB: The unqueued Slab allocator
From: David Miller <davem@davemloft.net>
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	<20070224142835.4c7a3207.kamezawa.hiroyu@jp.fujitsu.com>
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From: Christoph Lameter <clameter@engr.sgi.com>
Date: Fri, 23 Feb 2007 21:47:36 -0800 (PST)

> On Sat, 24 Feb 2007, KAMEZAWA Hiroyuki wrote:
> 
> > >From a viewpoint of a crash dump user, this merging will make crash dump
> > investigation very very very difficult.
> 
> The general caches already merge lots of users depending on their sizes. 
> So we already have the situation and we have tools to deal with it.

But this doesn't happen for things like biovecs, and that will
make debugging painful.

If a crash happens because of a corrupted biovec-256 I want to know
it was a biovec not some anonymous clone of kmalloc256.

Please provide at a minimum a way to turn the merging off.

I also agree with Andi in that merging could mess up how object type
local lifetimes help reduce fragmentation in object pools.

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