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Date: Mon, 28 Apr 2008 14:00:26 -0700
From: Arjan van de Ven <arjan@infradead.org>
To: Christoph Lameter <clameter@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>, akpm@linux-foundation.org, linux-mm@kvack.org,
       linux-kernel@vger.kernel.org,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [2/2] vmallocinfo: Add caller information
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On Tue, 29 Apr 2008 11:49:54 -0700 (PDT)
Christoph Lameter <clameter@sgi.com> wrote:

> On Mon, 28 Apr 2008, Arjan van de Ven wrote:
> 
> > > Sorry lost track of this issue. Adding stracktrace support is not
> > > a trivial thing and will change the basic handling of vmallocinfo.
> > > 
> > > Not sure if stacktrace support can be enabled without a penalty on
> > > various platforms. Doesnt this require stackframes to be
> > > formatted in a certain way?
> > 
> > it doesn't.
> 
> Hmmm... Why do we have CONFIG_FRAMEPOINTER then?

to make the backtraces more accurate.


> The current implementation of vmalloc_caller() follows what we have
> done with kmalloc_track_caller. Its low overhead and always on.

stacktraces aren't entirely free, the cost is O(nr of modules) unfortunately ;(