From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48134) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKkmH-0005LR-02 for qemu-devel@nongnu.org; Thu, 30 Jul 2015 06:09:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZKkmF-0005Zk-SQ for qemu-devel@nongnu.org; Thu, 30 Jul 2015 06:09:28 -0400 Received: from hall.aurel32.net ([2001:bc8:30d7:100::1]:36175) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKkmF-0005ZP-N2 for qemu-devel@nongnu.org; Thu, 30 Jul 2015 06:09:27 -0400 Date: Thu, 30 Jul 2015 12:09:25 +0200 From: Aurelien Jarno Message-ID: <20150730100925.GC23508@aurel32.net> References: <55B734A7.8040108@gmx.net> <55B870A9.4090008@gmx.net> <20150729150147.GO11361@aurel32.net> <55B99F95.8010603@gmx.net> <20150730075252.GT11361@aurel32.net> <55B9DD60.8020801@gmx.net> <20150730085500.GV11361@aurel32.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Aurelien Jarno Subject: Re: [Qemu-devel] Debian 7.8.0 SPARC64 on qemu - anything i can do to speedup the emulation? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Artyom Tarasenko Cc: qemu-devel , Dennis Luehring On 2015-07-30 11:35, Artyom Tarasenko wrote: > On Thu, Jul 30, 2015 at 10:55 AM, Aurelien Jarno wrote: > > On 2015-07-30 10:16, Dennis Luehring wrote: > >> Am 30.07.2015 um 09:52 schrieb Aurelien Jarno: > >> >On 2015-07-30 05:52, Dennis Luehring wrote: > >> >> Am 29.07.2015 um 17:01 schrieb Aurelien Jarno: > >> >> >The point is that emulation has a cost, and it's quite difficult to > >> >> >to lower it and thus improve the emulation speed. > >> >> > >> >> so its just not strange for you to see an 1/100...200 of the native x64 > >> >> speed under qemu/SPARC64 > >> >> i hoped that someone will jump up an shout "its impossible - it needs to be > >> >> a bug" ...sadly not > >> > > >> >Overall the ratio is more around 10, but in some specific cases where > >> >the TB cache is inefficient and TB can't be linked or with an > >> >inefficient MMU, a ratio of 100 is possible. > >> > >> > >> sysbench (0.4.12) --num-threads=1 --test=cpu --cpu-max-prime=2000 run > >> Host x64 : 1.3580s > >> Qemu SPARC64: 184.2532s > >> > >> sysbench shows nearly ration of 200 > > > > Note that when you say SPARC64 here, it's actually only the kernel, you > > are using a 32-bit userland. And that makes a difference. Here are my > > tests here: > > > > host (x86-64) 0.8976s > > sparc32 guest (sparc64 kernel) 99.6116s > > sparc64 guest (sparc64 kernel) 4.4908s > > Wow. That's quite a difference. What have you used as a sparc64 guest? > Are there any ready-to-use distributions, or have you built it from scratch? I am using Debian SPARC64 from debian-ports. But it's not really ready-to-use and often broken. -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurelien@aurel32.net http://www.aurel32.net