From: Avi Kivity <avi@redhat.com>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 11/11] KVM: MMU: improve write flooding detected
Date: Wed, 27 Jul 2011 14:08:26 +0300 [thread overview]
Message-ID: <4E2FF1AA.3020507@redhat.com> (raw)
In-Reply-To: <4E2FE674.8070202@cn.fujitsu.com>
On 07/27/2011 01:20 PM, Xiao Guangrong wrote:
> >> }
> >
> > I think this is a little dangerous. A guest kernel may be instantiating multiple gptes on a page fault, but guest userspace hits only one of them (the one which caused the page fault) - I think Windows does this, but I'm not sure.
> >
>
> I think this case is not bad: if the guest kernel need to write multiple gptes (>=3),
> it will cause many page fault, we do better zap the shadow page and let it become writable as
> soon as possible.
> (And, we have pte-fetch, it can quickly establish the mapping for a new shadow page)
Actually, what should save us is unsync pages. Why are we hitting this
path at all?
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-07-27 11:08 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-26 11:24 [PATCH 0/11] KVM: x86: optimize for guest page written Xiao Guangrong
2011-07-26 11:25 ` [PATCH 01/11] KVM: MMU: avoid pte_list_desc run out in kvm_mmu_pte_write Xiao Guangrong
2011-07-27 9:00 ` Avi Kivity
2011-07-27 9:37 ` Xiao Guangrong
2011-07-26 11:25 ` [PATCH 02/11] KVM: x86: cleanup pio/pout emulated Xiao Guangrong
2011-07-26 11:26 ` [PATCH 03/11] KVM: x86: fast emulate repeat string write instructions Xiao Guangrong
2011-07-26 12:27 ` Gleb Natapov
2011-07-26 13:53 ` Avi Kivity
2011-07-27 1:47 ` Xiao Guangrong
2011-07-27 4:26 ` Gleb Natapov
2011-07-27 6:32 ` Xiao Guangrong
2011-07-27 7:51 ` Gleb Natapov
2011-07-27 9:36 ` Xiao Guangrong
2011-07-27 9:04 ` Avi Kivity
2011-07-27 9:37 ` Xiao Guangrong
2011-07-26 11:28 ` [PATCH 04/11] KVM: MMU: do not mark access bit on pte write path Xiao Guangrong
2011-07-27 9:08 ` Avi Kivity
2011-07-27 10:04 ` Xiao Guangrong
2011-07-26 11:28 ` [PATCH 05/11] KVM: MMU: cleanup FNAME(invlpg) Xiao Guangrong
2011-07-26 11:29 ` [PATCH 06/11] KVM: MMU: fast prefetch spte on invlpg path Xiao Guangrong
2011-07-26 11:29 ` [PATCH 07/11] KVM: MMU: remove unnecessary kvm_mmu_free_some_pages Xiao Guangrong
2011-07-26 11:30 ` [PATCH 08/11] KVM: MMU: split kvm_mmu_pte_write function Xiao Guangrong
2011-07-26 11:31 ` [PATCH 09/11] KVM: MMU: remove the mismatch shadow page Xiao Guangrong
2011-07-27 9:11 ` Avi Kivity
2011-07-27 9:13 ` Avi Kivity
2011-07-27 10:05 ` Xiao Guangrong
2011-07-26 11:31 ` [PATCH 10/11] KVM: MMU: fix detecting misaligned accessed Xiao Guangrong
2011-07-27 9:15 ` Avi Kivity
2011-07-27 10:10 ` Xiao Guangrong
2011-07-26 11:32 ` [PATCH 11/11] KVM: MMU: improve write flooding detected Xiao Guangrong
2011-07-27 9:23 ` Avi Kivity
2011-07-27 10:20 ` Xiao Guangrong
2011-07-27 11:08 ` Avi Kivity [this message]
2011-07-28 2:43 ` Xiao Guangrong
-- strict thread matches above, loose matches on Subject: below --
2011-08-16 6:40 [PATCH 01/11] KVM: MMU: avoid pte_list_desc running out in kvm_mmu_pte_write Xiao Guangrong
2011-08-16 6:46 ` [PATCH 11/11] KVM: MMU: improve write flooding detected Xiao Guangrong
2011-08-23 8:00 ` Marcelo Tosatti
2011-08-23 10:55 ` Xiao Guangrong
2011-08-23 12:38 ` Marcelo Tosatti
2011-08-23 16:32 ` Xiao Guangrong
2011-08-23 19:09 ` Marcelo Tosatti
2011-08-23 20:16 ` Xiao Guangrong
2011-08-24 20:05 ` Marcelo Tosatti
2011-08-25 2:04 ` Marcelo Tosatti
2011-08-25 4:42 ` Avi Kivity
2011-08-25 13:21 ` Marcelo Tosatti
2011-08-25 14:06 ` Avi Kivity
2011-08-25 14:07 ` Avi Kivity
2011-08-25 7:40 ` Xiao Guangrong
2011-08-25 7:57 ` Xiao Guangrong
2011-08-25 13:47 ` Marcelo Tosatti
2011-08-26 3:18 ` Xiao Guangrong
2011-08-26 10:53 ` Marcelo Tosatti
2011-08-26 14:24 ` Xiao Guangrong
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