From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v2 1/9] KVM: add kvm_request_pending Date: Wed, 5 Apr 2017 20:30:03 +0200 Message-ID: References: <20170331160658.4331-1-drjones@redhat.com> <20170331160658.4331-2-drjones@redhat.com> <20170404153014.GL11752@cbox> <20170404164120.xvlvyebvcqoci5cu@kamzik.brq.redhat.com> <20170405131049.GD6369@potion> <20170405173918.GA27123@cbox> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 83F8340A7F for ; Wed, 5 Apr 2017 14:27:54 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u5wotuw2xSZJ for ; Wed, 5 Apr 2017 14:27:53 -0400 (EDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id E0E9740A74 for ; Wed, 5 Apr 2017 14:27:53 -0400 (EDT) In-Reply-To: <20170405173918.GA27123@cbox> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Christoffer Dall , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Cc: marc.zyngier@arm.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org List-Id: kvmarm@lists.cs.columbia.edu On 05/04/2017 19:39, Christoffer Dall wrote: >> Uses of vcpu->requests should already have barriers that take care of >> the ordering. I think the main reason for READ_ONCE() is to tell >> programmers that requests are special, but predictable. > > I don't know what to do with "special, but predictable", unfortunately. > In fact, I don't even think I know what you mean. I don't think it's special, but predictable. It's atomic, but with relaxed ordering. Paolo