From: Marcelo Tosatti <mtosatti@redhat.com>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Avi Kivity <avi@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: Fri, 26 Aug 2011 07:53:28 -0300 [thread overview]
Message-ID: <20110826105328.GA12612@amt.cnet> (raw)
In-Reply-To: <4E571069.2050701@cn.fujitsu.com>
On Fri, Aug 26, 2011 at 11:18:01AM +0800, Xiao Guangrong wrote:
> On 08/25/2011 09:47 PM, Marcelo Tosatti wrote:
>
> > I guess it is OK to be more trigger happy with zapping by ignoring
> > the accessed bit, clearing the flood counter on page fault.
> >
>
> Yeah, i like this way, is this patch good for you?
Looks fine, can you rerun kernbench?
> ================================
> Subject: [PATCH 11/11] KVM: MMU: improve write flooding detected
>
> Detecting write-flooding does not work well, when we handle page written, if
> the last speculative spte is not accessed, we treat the page is
> write-flooding, however, we can speculative spte on many path, such as pte
> prefetch, page synced, that means the last speculative spte may be not point
> to the written page and the written page can be accessed via other sptes, so
> depends on the Accessed bit of the last speculative spte is not enough
>
> Instead of detected page accessed, we can detect whether the spte is accessed
> after it is written, if the spte is not accessed but it is written frequently,
> we treat is not a page table or it not used for a long time
>
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
next prev parent reply other threads:[~2011-08-26 10:53 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
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 6:41 ` [PATCH 02/11] KVM: x86: tag the instructions which are used to write page table Xiao Guangrong
2011-08-22 14:32 ` Marcelo Tosatti
2011-08-22 14:36 ` Avi Kivity
2011-08-16 6:42 ` [PATCH 03/11] KVM: x86: retry non-page-table writing instruction Xiao Guangrong
2011-08-22 19:59 ` Marcelo Tosatti
2011-08-22 20:21 ` Xiao Guangrong
2011-08-22 20:42 ` Marcelo Tosatti
2011-08-16 6:42 ` [PATCH 04/11] KVM: x86: cleanup port-in/port-out emulated Xiao Guangrong
2011-08-16 6:43 ` [PATCH 05/11] KVM: MMU: do not mark access bit on pte write path Xiao Guangrong
2011-08-16 6:44 ` [PATCH 06/11] KVM: MMU: cleanup FNAME(invlpg) Xiao Guangrong
2011-08-16 6:44 ` [PATCH 07/11] KVM: MMU: fast prefetch spte on invlpg path Xiao Guangrong
2011-08-22 22:28 ` Marcelo Tosatti
2011-08-23 1:50 ` Xiao Guangrong
2011-08-16 6:45 ` [PATCH 08/11] KVM: MMU: remove unnecessary kvm_mmu_free_some_pages Xiao Guangrong
2011-08-16 6:45 ` [PATCH 09/11] KVM: MMU: split kvm_mmu_pte_write function Xiao Guangrong
2011-08-16 6:46 ` [PATCH 10/11] KVM: MMU: fix detecting misaligned accessed 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 [this message]
2011-08-26 14:24 ` Xiao Guangrong
-- strict thread matches above, loose matches on Subject: below --
2011-07-26 11:24 [PATCH 0/11] KVM: x86: optimize for guest page written 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
2011-07-28 2:43 ` Xiao Guangrong
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