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
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