From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <aliguori@us.ibm.com>
Cc: qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] Re: [Qemu-commits] [COMMIT 3086844] Instead of writing a zero page, madvise it away
Date: Mon, 22 Jun 2009 21:01:53 +0300 [thread overview]
Message-ID: <4A3FC711.9000200@redhat.com> (raw)
In-Reply-To: <4A3FC15D.1020705@us.ibm.com>
On 06/22/2009 08:37 PM, Anthony Liguori wrote:
> I'm saying, always enable dirty tracking from start-of-day with KVM.
> Then the QEMU dirty bitmap is always accurate. The trick is to never
> start resetting it until you need to do live migration.
That disables large pages and incurs a performance penalty (needlessly
setting bits).
> The idea being that once the dirty bits have been set, the overhead
> (hopefully) should be zero.
>
It's not zero. You also need to clear the bits somehow when you balloon.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2009-06-22 18:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200906221549.n5MFn3Qd015389@d03av02.boulder.ibm.com>
2009-06-22 16:12 ` [Qemu-devel] Re: [Qemu-commits] [COMMIT 3086844] Instead of writing a zero page, madvise it away Avi Kivity
2009-06-22 16:25 ` Anthony Liguori
2009-06-22 16:38 ` Avi Kivity
2009-06-22 16:58 ` Anthony Liguori
2009-06-22 17:12 ` Avi Kivity
2009-06-22 17:03 ` Anthony Liguori
2009-06-22 17:20 ` Avi Kivity
2009-06-22 17:37 ` Anthony Liguori
2009-06-22 18:01 ` Avi Kivity [this message]
2009-06-22 17:44 ` Anthony Liguori
2009-06-22 18:04 ` Avi Kivity
2009-06-22 19:38 ` Paul Brook
2009-06-22 19:49 ` Anthony Liguori
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