From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35714) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apxml-0006Ex-JK for qemu-devel@nongnu.org; Tue, 12 Apr 2016 08:51:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1apxmi-0004pv-9l for qemu-devel@nongnu.org; Tue, 12 Apr 2016 08:51:15 -0400 Received: from greensocs.com ([193.104.36.180]:49718) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apxmh-0004pH-T9 for qemu-devel@nongnu.org; Tue, 12 Apr 2016 08:51:12 -0400 References: <1459870344-16773-1-git-send-email-alex.bennee@linaro.org> <1459870344-16773-9-git-send-email-alex.bennee@linaro.org> <570C0E16.1030304@gmail.com> <87mvozyrmo.fsf@linaro.org> <570CED19.7000301@gmail.com> From: KONRAD Frederic Message-ID: <570CEF21.4000302@greensocs.com> Date: Tue, 12 Apr 2016 14:50:41 +0200 MIME-Version: 1.0 In-Reply-To: <570CED19.7000301@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC v2 08/11] tcg: add options for enabling MTTCG List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sergey Fedorov , Peter Maydell , =?UTF-8?Q?Alex_Benn=c3=a9e?= Cc: MTTCG Devel , Alvise Rigo , "Emilio G. Cota" , QEMU Developers , Mark Burton , Paolo Bonzini , "J. Kiszka" , Richard Henderson , Claudio Fontana , Peter Crosthwaite , =?UTF-8?Q?Andreas_F=c3=a4rber?= Le 12/04/2016 14:42, Sergey Fedorov a =C3=A9crit : > On 12/04/16 14:59, Peter Maydell wrote: >> On 12 April 2016 at 12:48, Alex Benn=C3=A9e w= rote: >>> Sergey Fedorov writes: >>>> Maybe we'd better use existing qemu accelerator framework and introd= uce >>>> "-machine accel=3Dmttcg" option? >>> My worry would be breaking existing code which assumes kvm | tcg. We >>> will want to enable mttcg by default for combos that work without hav= ing >>> to tweak tooling that already uses the -machine options. >> Comments from the peanut gallery: >> * We definitely want to just default to MTTCG where it works: >> users shouldn't have to add new command line switches to get the >> better performance etc, because in practice that won't happen >> * Anything that adds a new command line option at all has to >> be supported practically forever, so options that are only >> useful for a transitional period are worth thinking twice about > > Yes, but users may like to have an option to disable MTTCG for some > reason. I'm also concerned about icount mode: not sure how to account > virtual time when all vCPUs run in parallel. > Hi, I'm thinking the same, we don't have a solution for icount yet. The reverse execution support is probably badly broken as well. Fred > Kind regards, > Sergey >