From owner-freebsd-current@FreeBSD.ORG Fri Jul 3 08:20:46 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 386D51065676 for ; Fri, 3 Jul 2009 08:20:46 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (skuns.zoral.com.ua [91.193.166.194]) by mx1.freebsd.org (Postfix) with ESMTP id C62DB8FC17 for ; Fri, 3 Jul 2009 08:20:45 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id n638Kffi006173 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 3 Jul 2009 11:20:41 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.3/8.14.3) with ESMTP id n638KeAO035871; Fri, 3 Jul 2009 11:20:40 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.3/8.14.3/Submit) id n638KeGs035870; Fri, 3 Jul 2009 11:20:40 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 3 Jul 2009 11:20:40 +0300 From: Kostik Belousov To: Max Laier Message-ID: <20090703082040.GN2884@deviant.kiev.zoral.com.ua> References: <200907030204.51415.max@love2party.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="mT4yAvgikiid89S9" Content-Disposition: inline In-Reply-To: <200907030204.51415.max@love2party.net> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: Rafal Jaworowski , freebsd-current@freebsd.org, Jeff Roberson Subject: Re: MD5 test slowdown X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jul 2009 08:20:47 -0000 --mT4yAvgikiid89S9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 03, 2009 at 02:04:50AM +0200, Max Laier wrote: > On Thursday 02 July 2009 13:32:08 Rafal Jaworowski wrote: > > I'm observing some heavy slowdown seen with md5 test on PowerPC: > > > > 1. On the MPC8572 machine with today's HEAD I'm getting: > > > > # md5 -t > > MD5 time trial. Digesting 100000 10000-byte blocks ... done > > Digest =3D 766a2bb5d24bddae466c572bcabca3ee > > Time =3D 36.930565 seconds > > Speed =3D 27077842.000000 bytes/second > > > > 2. While a couple of months back it yielded 6x shorter times on this > > very same hardware, like this one: > > > > # md5 -t > > MD5 time trial. Digesting 100000 10000-byte blocks ... done > > Digest =3D 766a2bb5d24bddae466c572bcabca3ee > > Time =3D 6.027277 seconds > > Speed =3D 165912400.000000 bytes/second > > > > Timers work fine, the slowdown is real. I don't know if this is > > PowerPC related, and was wondering if anybody observed something > > similar on other archs perhaps? Any suggestions what could be causing > > this or where to look? I cannot see immediate suspects in the arch/ > > platform code. >=20 > "signifanctly slowdown of FreeBSD 8.0-CURRENT/amd64" to this mailing list= =20 > reports something that might be related. It seems there is a patch=20 > available, but not committed yet. Though I'm not sure about the nature o= f=20 > the problem exactly. Jeff? I want to make some points clear to avoid a confusion and spread of FUD. It seems we have at least three issues, all different: 1. Syscalls slowdown on amd64. To see this, you need to microbenchmark syscall enter/leave sequence. I doubt that it can be seen on any load except while (1) {getpid();} loops or such. The issue is valid _only_ for amd64. I developed the patch with the input from Jeff who confirmed that this slowdown is solved by the change. 2. There are enough independent reports of i/o slowdown to believe that some problem is real; but we have not seen numbers or detailed configurations or (most desirable) the revision after which the slowdown started. Note the i/o part. This report is for PPC (right ?) and for workload that is purely CPU-bounded. Please do not mix different issues. --mT4yAvgikiid89S9 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkpNv1gACgkQC3+MBN1Mb4hJ/ACfRAKVy4GIbLeR/f7IZbVYgEDp S4cAn1rhzLzrCL97SrH97SWTDbY1PmbZ =e+oN -----END PGP SIGNATURE----- --mT4yAvgikiid89S9--