From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 11/11] KVM: MMU: improve write flooding detected
Date: Thu, 25 Aug 2011 17:07:00 +0300 [thread overview]
Message-ID: <4E565704.5080007@redhat.com> (raw)
In-Reply-To: <4E5656E6.1090204@redhat.com>
On 08/25/2011 05:06 PM, Avi Kivity wrote:
> On 08/25/2011 04:21 PM, Marcelo Tosatti wrote:
>> On Thu, Aug 25, 2011 at 07:42:10AM +0300, Avi Kivity wrote:
>> > On 08/25/2011 05:04 AM, Marcelo Tosatti wrote:
>> > >>
>> > >> It could increase the flood count independently of the
>> accessed bit of
>> > >> the spte being updated, zapping after 3 attempts as it is now.
>> > >>
>> > >> But additionally reset the flood count if the gpte appears to
>> be valid
>> > >> (points to an existant gfn if the present bit is set, or if
>> its zeroed).
>> > >
>> > >Well not zero, as thats a common pattern for non ptes.
>> > >
>> >
>> > On 32-bit with 4GB RAM, practically anything is a valid gpte.
>>
>> The following could be required to consider a valid gpte, for write
>> flood detection purposes:
>>
>> - Must be present.
>> - PageCacheDisable must be unset.
>> - PageWriteThrough must be unset.
>>
>
> Unless the guest is using PAT.
>
And not swapping.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2011-08-25 14:07 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 [this message]
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
-- 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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