From: Gleb Natapov <gleb@redhat.com>
To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: avi.kivity@gmail.com, mtosatti@redhat.com, pbonzini@redhat.com,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH 09/12] KVM: MMU: introduce pte-list lockless walker
Date: Wed, 28 Aug 2013 12:46:30 +0300 [thread overview]
Message-ID: <20130828094630.GR22899@redhat.com> (raw)
In-Reply-To: <521DC3FD.1020507@linux.vnet.ibm.com>
On Wed, Aug 28, 2013 at 05:33:49PM +0800, Xiao Guangrong wrote:
> > Or what if desc is moved to another rmap, but then it
> > is moved back to initial rmap (but another place in the desc list) so
> > the check here will not catch that we need to restart walking?
>
> It is okay. We always add the new desc to the head, then we will walk
> all the entires under this case.
>
Which races another question: What if desc is added in front of the list
behind the point where lockless walker currently is?
> Right?
Not sure. While lockless walker works on a desc rmap can be completely
destroyed and recreated again. It can be any order.
--
Gleb.
next prev parent reply other threads:[~2013-08-28 9:47 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-30 13:01 [RFC PATCH 00/12] KVM: MMU: locklessly wirte-protect Xiao Guangrong
2013-07-30 13:01 ` [PATCH 01/12] KVM: MMU: remove unused parameter Xiao Guangrong
2013-08-29 7:22 ` Gleb Natapov
2013-07-30 13:02 ` [PATCH 02/12] KVM: MMU: properly check last spte in fast_page_fault() Xiao Guangrong
2013-07-30 13:02 ` [PATCH 03/12] KVM: MMU: lazily drop large spte Xiao Guangrong
2013-08-02 14:55 ` Marcelo Tosatti
2013-08-02 15:42 ` Xiao Guangrong
2013-08-02 20:27 ` Marcelo Tosatti
2013-08-02 22:56 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 04/12] KVM: MMU: log dirty page after marking spte writable Xiao Guangrong
2013-07-30 13:26 ` Paolo Bonzini
2013-07-31 7:25 ` Xiao Guangrong
2013-08-07 1:48 ` Marcelo Tosatti
2013-08-07 4:06 ` Xiao Guangrong
2013-08-08 15:06 ` Marcelo Tosatti
2013-08-08 16:26 ` Xiao Guangrong
2013-11-20 0:29 ` Marcelo Tosatti
2013-11-20 0:35 ` Marcelo Tosatti
2013-11-20 14:20 ` Xiao Guangrong
2013-11-20 19:47 ` Marcelo Tosatti
2013-11-21 4:26 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 05/12] KVM: MMU: add spte into rmap before logging dirty page Xiao Guangrong
2013-07-30 13:27 ` Paolo Bonzini
2013-07-31 7:33 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 06/12] KVM: MMU: flush tlb if the spte can be locklessly modified Xiao Guangrong
2013-08-28 7:23 ` Gleb Natapov
2013-08-28 7:50 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 07/12] KVM: MMU: redesign the algorithm of pte_list Xiao Guangrong
2013-08-28 8:12 ` Gleb Natapov
2013-08-28 8:37 ` Xiao Guangrong
2013-08-28 8:58 ` Gleb Natapov
2013-08-28 9:19 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 08/12] KVM: MMU: introduce nulls desc Xiao Guangrong
2013-08-28 8:40 ` Gleb Natapov
2013-08-28 8:54 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 09/12] KVM: MMU: introduce pte-list lockless walker Xiao Guangrong
2013-08-28 9:20 ` Gleb Natapov
2013-08-28 9:33 ` Xiao Guangrong
2013-08-28 9:46 ` Gleb Natapov [this message]
2013-08-28 10:13 ` Xiao Guangrong
2013-08-28 10:49 ` Gleb Natapov
2013-08-28 12:15 ` Xiao Guangrong
2013-08-28 13:36 ` Gleb Natapov
2013-08-29 6:50 ` Xiao Guangrong
2013-08-29 9:08 ` Gleb Natapov
2013-08-29 9:31 ` Xiao Guangrong
2013-08-29 9:51 ` Gleb Natapov
2013-08-29 11:26 ` Xiao Guangrong
2013-08-30 11:38 ` Gleb Natapov
2013-09-02 7:02 ` Xiao Guangrong
2013-08-29 9:31 ` Gleb Natapov
2013-08-29 11:33 ` Xiao Guangrong
2013-08-29 12:02 ` Xiao Guangrong
2013-08-30 11:44 ` Gleb Natapov
2013-09-02 8:50 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 10/12] KVM: MMU: allow locklessly access shadow page table out of vcpu thread Xiao Guangrong
2013-08-07 13:09 ` Takuya Yoshikawa
2013-08-07 13:19 ` Xiao Guangrong
2013-08-29 9:10 ` Gleb Natapov
2013-08-29 9:25 ` Xiao Guangrong
2013-07-30 13:02 ` [PATCH 11/12] KVM: MMU: locklessly write-protect the page Xiao Guangrong
2013-07-30 13:02 ` [PATCH 12/12] KVM: MMU: clean up spte_write_protect Xiao Guangrong
2013-07-30 13:11 ` [RFC PATCH 00/12] KVM: MMU: locklessly wirte-protect Xiao Guangrong
2013-08-03 5:09 ` Takuya Yoshikawa
2013-08-04 14:15 ` Xiao Guangrong
2013-08-29 7:16 ` Gleb Natapov
2013-08-06 13:16 ` Xiao Guangrong
2013-08-08 17:38 ` Paolo Bonzini
2013-08-09 4:51 ` 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=20130828094630.GR22899@redhat.com \
--to=gleb@redhat.com \
--cc=avi.kivity@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mtosatti@redhat.com \
--cc=pbonzini@redhat.com \
--cc=xiaoguangrong@linux.vnet.ibm.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).