From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58479) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azjG9-0007Yk-A2 for qemu-devel@nongnu.org; Mon, 09 May 2016 07:21:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1azjG6-0003i2-Sz for qemu-devel@nongnu.org; Mon, 09 May 2016 07:21:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37763) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azjG6-0003hx-Nq for qemu-devel@nongnu.org; Mon, 09 May 2016 07:21:54 -0400 References: <20160425152528.GA16402@flamenco> <1461627983-32563-1-git-send-email-cota@braap.org> <87shy8ev7c.fsf@linaro.org> <20160430034035.GA31609@flamenco> From: Paolo Bonzini Message-ID: <573072CE.3070808@redhat.com> Date: Mon, 9 May 2016 13:21:50 +0200 MIME-Version: 1.0 In-Reply-To: <20160430034035.GA31609@flamenco> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC v3] translate-all: protect code_gen_buffer with RCU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Emilio G. Cota" , =?UTF-8?Q?Alex_Benn=c3=a9e?= Cc: QEMU Developers , MTTCG Devel , Peter Crosthwaite , Richard Henderson , Sergey Fedorov On 30/04/2016 05:40, Emilio G. Cota wrote: >> The tb_flush >> > is a fairly rare occurrence its not like its on the critical performance >> > path (although of course pathological cases are possible). > This is what I thought from the beginning, but wanted to give this > alternative a go anyway to see if it was feasible. > > On my end I won't do any more work on this approach. Will go back > to locks, despite Paolo's (justified) dislike for them =) Which locks? tb_lock during tb_find_fast? The problem with that was that it slowed down everything a lot, wasn't it? To me, the RCU idea is not really about making tb_flush (the rare case) faster; it was more about keeping the rest simple and fast. Paolo