From owner-freebsd-current@FreeBSD.ORG Fri Mar 21 05:06:50 2008 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 35CF4106566C for ; Fri, 21 Mar 2008 05:06:50 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from relay02.kiev.sovam.com (relay02.kiev.sovam.com [62.64.120.197]) by mx1.freebsd.org (Postfix) with ESMTP id C3B308FC22 for ; Fri, 21 Mar 2008 05:06:49 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from [212.82.216.226] (helo=skuns.kiev.zoral.com.ua) by relay02.kiev.sovam.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1JcZSm-000L1e-05 for freebsd-current@freebsd.org; Fri, 21 Mar 2008 07:06:48 +0200 Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by skuns.kiev.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m2L56gfR014601 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 21 Mar 2008 07:06:42 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m2L56TUu096259; Fri, 21 Mar 2008 07:06:29 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2/Submit) id m2L56TRE096258; Fri, 21 Mar 2008 07:06:29 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 21 Mar 2008 07:06:29 +0200 From: Kostik Belousov To: Kip Macy Message-ID: <20080321050629.GS10374@deviant.kiev.zoral.com.ua> References: <20080321030254.GA98444@troutmask.apl.washington.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XhDIt1ZqED2V8RHq" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: ClamAV version 0.91.2, clamav-milter version 0.91.2 on 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=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on skuns.kiev.zoral.com.ua X-Scanner-Signature: 362d5034abbfed611c52a2913ea5ff69 X-DrWeb-checked: yes X-SpamTest-Envelope-From: kostikbel@gmail.com X-SpamTest-Group-ID: 00000000 X-SpamTest-Header: Not Detected X-SpamTest-Info: Profiles 2450 [Mar 20 2008] X-SpamTest-Info: helo_type=3 X-SpamTest-Method: none X-SpamTest-Rate: 0 X-SpamTest-Status: Not detected X-SpamTest-Status-Extended: not_detected X-SpamTest-Version: SMTP-Filter Version 3.0.0 [0278], KAS30/Release Cc: freebsd-current@freebsd.org, Steve Kargl Subject: Re: Extremely slooooow __sys_ftruncate? 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, 21 Mar 2008 05:06:50 -0000 --XhDIt1ZqED2V8RHq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Mar 20, 2008 at 08:48:17PM -0700, Kip Macy wrote: > "truncate" may be synchronous on FreeBSD - almost nothing is on Linux. Partial truncate is synchronous for UFS mounts. Full truncate (to 0 lenght) also may become synchronous under high i/o pressure. >=20 > -Kip >=20 > On Thu, Mar 20, 2008 at 8:02 PM, Steve Kargl > wrote: > > In the process of helping to debug a problem with gcc-4.4.0 > > (actually a gfortran problem), I run gprof on the executable. > > The profile shows that __sys_ftruncate is extremely slow. > > > > % cumulative self self total > > time seconds seconds calls ms/call ms/call name > > 85.6 6.05 6.05 51830 0.12 0.12 __sys_ftruncate = [2] > > 5.6 6.44 0.40 0 100.00% .mcount (101) > > 1.7 6.56 0.12 51872 0.00 0.00 _lseek [5] > > 1.6 6.67 0.11 52055 0.00 0.00 sigprocmask [6] > > 0.8 6.73 0.06 103687 0.00 0.00 memset [14] > > 0.4 6.76 0.03 488 0.06 0.06 __sys_write [18] > > 0.4 6.79 0.03 0 100.00% formatted_transfe= r_scalar > > > > time ./z > > 184.21 real 0.98 user 6.57 sys > > > > This program should finish well under 184 seconds. The same program > > and exact same gcc/gfortran source on linux shows > > real 0m0.555s user 0m0.103s sys 0m0.452s > > > > Is __sys_ftruncate known to have performance problems? --XhDIt1ZqED2V8RHq Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (FreeBSD) iEYEARECAAYFAkfjQlQACgkQC3+MBN1Mb4hdtwCfYMtBdsqyFgSONLhtnhOY044I pMYAn0G9FLvgyqaoY2Rhbnq8p94Dco71 =DIQM -----END PGP SIGNATURE----- --XhDIt1ZqED2V8RHq--