From: Avi Kivity <avi@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>,
mtosatti@redhat.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com
Subject: Re: [PATCH 0/4] KVM: srcu-less dirty logging
Date: Tue, 28 Feb 2012 12:03:27 +0200 [thread overview]
Message-ID: <4F4CA66F.8090109@redhat.com> (raw)
In-Reply-To: <1330003524.11248.11.camel@twins>
On 02/23/2012 03:25 PM, Peter Zijlstra wrote:
> On Thu, 2012-02-23 at 20:33 +0900, Takuya Yoshikawa wrote:
> > - Stop allocating extra dirty bitmap buffer area
> >
> > According to Peter, mmu_notifier has become preemptible. If we can
> > change mmu_lock from spin_lock to mutex_lock, as Avi said before, this
> > would be staightforward because we can use __put_user() right after
> > xchg() with the mmu_lock held
>
> So the 'only' thing to consider is running the end result with lockdep
> enabled since the mmu locks are rather deep in the nesting tree its very
> easy to accidentally cause inversions.
There will be an inversion for sure, if __put_user() faults and triggers
an mmu notifier (perhaps directly, perhaps through an allocation that
triggers a swap).
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-02-28 10:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-23 11:33 [PATCH 0/4] KVM: srcu-less dirty logging Takuya Yoshikawa
2012-02-23 11:33 ` [PATCH 1/4] KVM: MMU: Split the main body of rmap_write_protect() off from others Takuya Yoshikawa
2012-02-23 11:34 ` [PATCH 2/4] KVM: Avoid checking huge page mappings in get_dirty_log() Takuya Yoshikawa
2012-02-23 11:35 ` [PATCH 3/4] KVM: Switch to srcu-less get_dirty_log() Takuya Yoshikawa
2012-02-28 11:46 ` Avi Kivity
2012-02-29 7:49 ` Takuya Yoshikawa
2012-02-29 9:25 ` Avi Kivity
2012-02-29 10:16 ` Takuya Yoshikawa
2012-02-29 12:27 ` Avi Kivity
2012-02-29 14:18 ` Takuya Yoshikawa
2012-02-23 11:36 ` [PATCH 4/4] KVM: Remove unused dirty_bitmap_head and nr_dirty_pages Takuya Yoshikawa
2012-02-23 13:25 ` [PATCH 0/4] KVM: srcu-less dirty logging Peter Zijlstra
2012-02-28 10:03 ` Avi Kivity [this message]
2012-02-29 4:30 ` Takuya Yoshikawa
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=4F4CA66F.8090109@redhat.com \
--to=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mtosatti@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=yoshikawa.takuya@oss.ntt.co.jp \
/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).