From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48824) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yk94D-0005gj-IO for qemu-devel@nongnu.org; Mon, 20 Apr 2015 06:36:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yk94A-0002rh-Cj for qemu-devel@nongnu.org; Mon, 20 Apr 2015 06:36:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37308) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yk94A-0002rF-5G for qemu-devel@nongnu.org; Mon, 20 Apr 2015 06:36:38 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t3KAaaPG022727 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 20 Apr 2015 06:36:36 -0400 Date: Mon, 20 Apr 2015 11:36:34 +0100 From: Stefan Hajnoczi Message-ID: <20150420103634.GB1313@stefanha-thinkpad.redhat.com> References: <1429160256-27231-1-git-send-email-famz@redhat.com> <20150416130316.GF27070@stefanha-thinkpad.redhat.com> <20150417020230.GF28705@ad.nay.redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="R3G7APHDIzY6R/pk" Content-Disposition: inline In-Reply-To: <20150417020230.GF28705@ad.nay.redhat.com> Subject: Re: [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_poll abstraction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Kevin Wolf , Paolo Bonzini , qemu-devel@nongnu.org --R3G7APHDIzY6R/pk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 17, 2015 at 10:02:30AM +0800, Fam Zheng wrote: > On Thu, 04/16 14:03, Stefan Hajnoczi wrote: > > On Thu, Apr 16, 2015 at 12:57:29PM +0800, Fam Zheng wrote: > > > v3: Rebase to master for 2.4. > > > Although epoll_pwait1 syscall is still being worked on [1], the Q= EMU part > > > (if any) will base on this, so let's merge it first. > > > =20 > > > That part is not included in this version because I'm still evalu= ating by > > > comparing epoll_pwait1 with epoll+timerfd as with current master = they seem > > > to be really close. > > >=20 > > > [1]: http://www.spinics.net/lists/linux-api/msg08216.html > > >=20 > > > v2: Emulate nanoseconds precison of timeout with ppoll and timerfd. > > > Their performance is on par with each other, but both much better= than > > > qemu.git: > > >=20 > > > syscall high # of fd low # of fd > > > ------------------------------------------------- > > > qemu.git(ppoll) 44 96 > > > ppoll+epoll 85 101 > > > timerfd+epoll 87 109 > > >=20 > > > (In high # of fd case, 3 activated but idle virtio-console devices are > > > attached, which will add us hundereds of fds to poll) > >=20 > > Have you rerun benchmarks with this patch series? >=20 > Yes, here: >=20 > syscall high # of fd low # of fd > (Unit MB/s) (Unit MB/s) > ------------------------------------------------- > qemu.git(ppoll) 24 73 > ppoll+epoll 49 77 > timerfd+epoll 49 82 Nice. Weird that the results are much lower than the v2 results, but maybe the host changed? > >=20 > > I wonder how the ppoll-only performance changes. It seems like there > > are now additional copies of information and > > corresponding malloc/realloc/frees. Please add a ppoll-only column hosts so we can be confident that the non-epoll code works. It will also show that non-Linux POSIX hosts haven't regressed. Thanks, Stefan --R3G7APHDIzY6R/pk Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJVNNayAAoJEJykq7OBq3PIZCoIAKOsoeTj2jqzR6D1jouL94eO vlKOQErdPHWpsmn89dioLTSDpvvU3nGcsJq9KDi0FZ9gz6XSsHo1TMH19YaUy2oR QHWj906MaOb5GgF0EczIxtaT7ugDSVGG7D1z5hbwqd/IsklCVWa+CbMyskMhwVBm AReol4W0yoDV0K2lfzP4LJxC0TyXE6KGrunaYJsp1dRX+/5M8NlQSvKjON8rgJoy cOmdEbzdduq/eb9ktGXFdinbdCvtqKauOnaS9W9Air+8ojD1p+9HE09mJ19Nmltw rlnJLnfHcKBUoKkyiZFifk3HzIOcSJWAValszOGyqFkLW/ep4z1GuDVx4igDUe0= =BljZ -----END PGP SIGNATURE----- --R3G7APHDIzY6R/pk--