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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] Re: memory usage and ioports
Date: Mon, 19 Nov 2007 16:17:26 +0000
References: <20071119152016.GE6331@implementation.uk.xensource.com>
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To: qemu-devel@nongnu.org
Cc: Samuel Thibault <samuel.thibault@eu.citrix.com>

On Monday 19 November 2007, Samuel Thibault wrote:
> Samuel Thibault, le Mon 19 Nov 2007 15:20:16 +0000, a =E9crit :
> > Qemu currently uses 6 65k tables of pointers for handling ioports, which
> > makes 3MB on 64bit machines. There's a comment that says "XXX: use a two
> > level table to limit memory usage". But wouldn't it be more simple and
> > effective to just allocate them through mmap() and when a NULL pointer
> > is read, call the default handlers?
>
> For the ioport_opaque array (500KB on 64bit), it's much simpler, as the
> attached patch suggests.

AFAICS This makes absolutely no difference to memory usage.

Paul