From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:59166) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QETGB-0001kL-1z for qemu-devel@nongnu.org; Mon, 25 Apr 2011 17:24:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QETG9-0006qX-Sf for qemu-devel@nongnu.org; Mon, 25 Apr 2011 17:23:58 -0400 Received: from hall.aurel32.net ([88.191.126.93]:41443) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QETG9-0006px-Nb for qemu-devel@nongnu.org; Mon, 25 Apr 2011 17:23:57 -0400 Date: Mon, 25 Apr 2011 20:35:37 +0200 From: Aurelien Jarno Message-ID: <20110425183537.GF6181@volta.aurel32.net> References: <20110413201615.GA15989@volta.aurel32.net> <4DA69EDB.8080600@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <4DA69EDB.8080600@web.de> Subject: Re: [Qemu-devel] [PATCH v2 0/3] io-thread optimizations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Paolo Bonzini , Anthony Liguori , Marcelo Tosatti , qemu-devel@nongnu.org On Thu, Apr 14, 2011 at 09:14:35AM +0200, Jan Kiszka wrote: > On 2011-04-13 22:16, Aurelien Jarno wrote: > > On Mon, Apr 11, 2011 at 10:27:41PM +0200, Jan Kiszka wrote: > >> These patches were posted before. They bring down the overhead of the > >> io-thread mode for TCG here, specifically when emulating SMP. > >> > >> The major change in this version, besides rebasing, is the exclusion of > >> KVM from the main loop polling optimization. > >> > >> > >> > >> Jan Kiszka (3): > >> Do not drop global mutex for polled main loop runs > >> Poll main loop after I/O events were received > >> Do not kick vcpus in TCG mode > >> > >> cpus.c | 2 +- > >> sysemu.h | 2 +- > >> vl.c | 22 ++++++++++++++++------ > >> 3 files changed, 18 insertions(+), 8 deletions(-) > >> > > > > Thanks for working on improving the io-thread with TCG. Your patches > > make sense, but they don't seems to fix the slowdown observed when > > enabling the io-thread. Well maybe they were not supposed to. This is > > for example the results of netperf between guest and host using virtio: > > > > no io-thread 122 MB/s > > io-thread 97 MB/s > > io-thread + patches 98 MB/s > > > > Can you capture ftraces of io-thread enabled & disabled runs? They just > need to cover a hand full of frames. > >>From what I have been able to get from the ftraces documentation, it's possible multiple tracers. Which tracers would you like to use there? The best would be a set of command lines to run. -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net