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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4E565704.5080007@redhat.com \
--to=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mtosatti@redhat.com \
--cc=xiaoguangrong@cn.fujitsu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.