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Date: Wed, 5 Jan 2011 21:35:18 +0100
From: Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] add MADV_DONTFORK to guest physical memory
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To: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, Andreas =?iso-8859-1?Q?F=E4rber?= <andreas.faerber@web.de>, Anthony Liguori <aliguori@us.ibm.com>, Alexander Graf <agraf@suse.de>, "qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>

On Wed, Jan 05, 2011 at 02:26:19PM -0600, Michael Roth wrote:
> Yah you're right, but I've seen several discussions about using mempath 
> for tmpfs/ram-backed files for things like numa/zram/etc so tend to 
> think of it as something potentially more than just a hook for 
> hugetlbfs, which is becoming less and less useful. But the MADV_DONTFORK 
> stuff should still be immediately applicable.

Yes, MADV_DONTFORK should be set all on all guest physical memory
without options so I hope the new patch I just posted is fine to stop
the spurious -ENOMEM failures in fork.

The ksm part should go incremental but 99% of it will be about
changing the command line, making the madvise conditional will be
trivial as well.