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Subject: Re: [PATCH] Add kmemleak annotations to lmb.c
From: Catalin Marinas <catalin.marinas@arm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Date: Fri, 14 Aug 2009 09:25:13 +0100
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Cc: linuxppc-dev@ozlabs.org, "David S. Miller" <davem@davemloft.net>
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On Fri, 2009-08-14 at 17:56 +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2009-08-13 at 16:40 +0100, Catalin Marinas wrote:
> > On Thu, 2009-08-13 at 13:01 +1000, Michael Ellerman wrote:
> > > We don't actually want kmemleak to track the lmb allocations, so we
> > > pass min_count as 0. However telling kmemleak about lmb allocations
> > > allows it to scan that memory for pointers to other memory that is
> > > tracked by kmemleak, ie. slab allocations etc.
> > 
> > Looks alright to me (though I haven't tested it). You can add a
> > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> 
> Actually, Milton pointed to me that we may not want to allow all
> LMB chunks to be scanned by kmemleaks, things like the DART hole
> that's taken out of the linear mapping for example may need to
> be avoided, though I'm not sure what would be the right way to
> do it.

I suspect there are more blocks to be scanned than those that shouldn't,
so maybe ignore the latter explicitly using kmemleak_ignore(). This was
raised recently on x86_64 as well which has a memory hole for some
aperture - http://lkml.org/lkml/2009/8/13/237.

-- 
Catalin