From: Paolo Bonzini <pbonzini@redhat.com>
To: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: quintela@redhat.com,
qemu-devel qemu-devel <qemu-devel@nongnu.org>,
Michael Roth <mdroth@linux.vnet.ibm.com>,
Orit Wasserman <owasserm@redhat.com>,
benoit.hudzia@sap.com, chegu_vinod@hp.com
Subject: Re: [Qemu-devel] Migration ToDo list
Date: Wed, 14 Nov 2012 03:20:08 +0100 [thread overview]
Message-ID: <50A2FFD8.1050909@redhat.com> (raw)
In-Reply-To: <20121114021422.GI12124@valinux.co.jp>
Il 14/11/2012 03:14, Isaku Yamahata ha scritto:
>> > Identifying ballooned zero pages is useful, because those cause the
>> > clear_page calls in the kernel even in a guest that has been running for
>> > a while.
>> >
>> > But a generic solution doesn't really matter, because is_dup_page and
>> > clear_page shouldn't really be in the profile in practice, except in
>> > microbenchmarks.
> I guess mincore(2) can be used as easy way to detect non-mapped page.
> This is just implementation detail anyway.
Doesn't work if the page is swapped, doesn't it?
But I wonder if the clear_page occurrences are because of the problem
described recently on LWN (http://lwn.net/Articles/517465/), and so
really more of a kernel bug than anything else.
Paolo
next prev parent reply other threads:[~2012-11-14 2:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-13 16:18 [Qemu-devel] Migration ToDo list Juan Quintela
2012-11-13 16:28 ` Paolo Bonzini
2012-11-13 17:09 ` Orit Wasserman
2012-11-13 17:16 ` Paolo Bonzini
2012-11-14 2:14 ` Isaku Yamahata
2012-11-14 2:20 ` Paolo Bonzini [this message]
2012-11-14 2:31 ` Isaku Yamahata
2012-11-13 16:40 ` Orit Wasserman
2012-11-13 16:48 ` Chegu Vinod
2012-11-13 16:57 ` Orit Wasserman
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