From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [Qemu-devel] [RFC] create a single workqueue for each vm to update vm irq routing table Date: Thu, 28 Nov 2013 12:31:29 +0100 Message-ID: <52972991.1050407@redhat.com> References: <5294BC3B.6070902@redhat.com> <5297050E.6000700@redhat.com> <20131128091903.GA4609@kernel.org> <5297118C.3050104@cloudius-systems.com> <529712A1.8090207@redhat.com> <5297181B.3090109@cloudius-systems.com> <52971D86.60601@redhat.com> <20131128110915.GD5822@minantech.com> <529724B0.80405@redhat.com> <20131128112348.GF5822@minantech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , "Zhanghaoyu (A)" , Gleb Natapov , Avi Kivity , "Huangweidong (C)" , KVM , "Michael S. Tsirkin" , "Jinxin (F)" , Luonengjun , "qemu-devel@nongnu.org" , Zanghongyong To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:27244 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751653Ab3K1Lbo (ORCPT ); Thu, 28 Nov 2013 06:31:44 -0500 In-Reply-To: <20131128112348.GF5822@minantech.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 28/11/2013 12:23, Gleb Natapov ha scritto: >>> > > Unless what ? :) Unless reader is scheduled out? >> > >> > Yes. Or unless my brain is scheduled out in the middle of a sentence. >> > > So we will have to disable preemption in a reader to prevent big latencies for > a writer, no? I don't think that's necessary. The writer itself could also be scheduled out, and the reader critical sections are really small. Let's wait for Zhang to try SRCU and report back. Paolo