From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:56307) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QEcp3-0007ga-70 for qemu-devel@nongnu.org; Tue, 26 Apr 2011 03:36:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QEcp2-0001bf-5w for qemu-devel@nongnu.org; Tue, 26 Apr 2011 03:36:37 -0400 Received: from fmmailgate01.web.de ([217.72.192.221]:57620) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QEcp1-0001bZ-PV for qemu-devel@nongnu.org; Tue, 26 Apr 2011 03:36:36 -0400 Message-ID: <4DB675FE.1030900@web.de> Date: Tue, 26 Apr 2011 09:36:30 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <20110413201615.GA15989@volta.aurel32.net> <4DA69EDB.8080600@web.de> <20110425183537.GF6181@volta.aurel32.net> In-Reply-To: <20110425183537.GF6181@volta.aurel32.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig8A5892AED7FD6120EE397E76" Sender: jan.kiszka@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: Aurelien Jarno Cc: Paolo Bonzini , Anthony Liguori , Marcelo Tosatti , qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig8A5892AED7FD6120EE397E76 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable On 2011-04-25 20:35, Aurelien Jarno wrote: > 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 th= e >>>> 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 virti= o: >>> >>> 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 jus= t >> need to cover a hand full of frames. >> >=20 > 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. Sorry, of course: Just download, build & install trace-cmd [1], then execute "trace-cmd record -b 16000 -e all" while qemu is running. The result is written to trace.dat in the current directory. Visualize it via "trace-cmd report" (or kernelshark if you built that as well). Jan [1] git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git --------------enig8A5892AED7FD6120EE397E76 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk22dgEACgkQitSsb3rl5xSXAgCeNus9CsdUfMDrqjH9jXNo20yL 8PUAoOqTD2IPNjIdNJj+lklOmYPe31lO =vckp -----END PGP SIGNATURE----- --------------enig8A5892AED7FD6120EE397E76--