From: Paolo Bonzini <pbonzini@redhat.com>
To: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Cc: Gleb Natapov <gleb@kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kvm: fix waitqueue_active without memory barrier in virt/kvm/async_pf.c
Date: Fri, 9 Oct 2015 12:26:47 +0200 [thread overview]
Message-ID: <56179667.8010609@redhat.com> (raw)
In-Reply-To: <17EC94B0A072C34B8DCF0D30AD16044A02874CB2@BPXM09GP.gisp.nec.co.jp>
On 09/10/2015 11:04, Kosuke Tatsukawa wrote:
> smp_store_mb() called from set_current_state(), which is called from
> prepare_to_wait() should prevent reordering such as below from
> happening. wait_event*() also calls set_current_state() inside.
Ah, I missed that set_current_state has a memory barrier in it. The
patch is okay, but please expand the comment to say that this memory
barrier pairs with prepare_to_wait's set_current_state().
Paolo
next prev parent reply other threads:[~2015-10-09 10:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-09 0:35 [PATCH] kvm: fix waitqueue_active without memory barrier in virt/kvm/async_pf.c Kosuke Tatsukawa
2015-10-09 8:45 ` Paolo Bonzini
2015-10-09 8:50 ` Peter Zijlstra
2015-10-09 10:24 ` Paolo Bonzini
2015-10-09 9:04 ` Kosuke Tatsukawa
2015-10-09 10:26 ` Paolo Bonzini [this message]
2015-10-09 12:21 ` Kosuke Tatsukawa
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=56179667.8010609@redhat.com \
--to=pbonzini@redhat.com \
--cc=gleb@kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tatsu@ab.jp.nec.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.