From owner-freebsd-current@FreeBSD.ORG Sat Dec 14 21:51:15 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E4A35F4D for ; Sat, 14 Dec 2013 21:51:15 +0000 (UTC) Received: from nm24-vm8.bullet.mail.ird.yahoo.com (nm24-vm8.bullet.mail.ird.yahoo.com [212.82.109.199]) by mx1.freebsd.org (Postfix) with SMTP id 274CE1152 for ; Sat, 14 Dec 2013 21:51:14 +0000 (UTC) Received: from [77.238.189.237] by nm24.bullet.mail.ird.yahoo.com with NNFMP; 14 Dec 2013 21:44:16 -0000 Received: from [46.228.39.95] by tm18.bullet.mail.ird.yahoo.com with NNFMP; 14 Dec 2013 21:44:16 -0000 Received: from [127.0.0.1] by smtp132.mail.ir2.yahoo.com with NNFMP; 14 Dec 2013 21:44:16 -0000 X-Yahoo-Newman-Id: 896122.12838.bm@smtp132.mail.ir2.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: Y.ETA9EVM1kHxHcf.MNSxv7axwd2WCWR4dUfGmBO0YQt3SN 0WiHA4OJx988Y9eC.fU72VmqXe7cztWEFv1THPPzDStXtlUUgJUHT04PjmDT Y3wUJaTTHsYqT4Hb.2XUe7gItx4bvSPwM1UO94yEk6NujXsDd_YMEKx29LIa VlHFej0sZInSJ6nfp88tjbm4.oyRj.MR9NN7bX3Mxgx83jMgldneOKSIzEae ijcikifobJ6Gs90DuaXrBFrvANeC.ByoIQhiBaVZdDFQY1bOuiTwcu70mKE. eLKg5Rrx7wfMwbpcZTTVn5hwczi1g5PI.edUQ2IgKINU.KU_3NrqK6H4X5OU 8sP6zJMOBuH7caR.P0_7BzlEIIm2P.O1qSK6Lt2RmNw3sb9ngUl8Pfh39Aek .Nlgqpat58ZsvN6x1UVpw9AexYbmKthvzrndiLItpJLl5CLYyxEobBjrmzEf xLLhYnm4F4UCSp2MgZfekhZwWkRcTXuip40iCJvFvhl1Y0XN9f6QazOH5IYC gxxLGo3u_HwlSu2q3v99O5XTMdEQuY1abLluxJKlWXFYGUQ7cNFjlTLAMtpw 3BV8HQ2d_9BtP7A-- X-Yahoo-SMTP: iDf2N9.swBDAhYEh7VHfpgq0lnq. X-Rocket-Received: from [192.168.119.26] (se@84.154.102.88 with plain [188.125.69.59]) by smtp132.mail.ir2.yahoo.com with SMTP; 14 Dec 2013 21:44:16 +0000 UTC Message-ID: <52ACD12A.5020906@freebsd.org> Date: Sat, 14 Dec 2013 22:44:10 +0100 From: Stefan Esser User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: freebsd-current@freebsd.org Subject: SVN commit 259045 breaks -CURRENT X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kib@freebsd.org X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.17 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: Sat, 14 Dec 2013 21:51:16 -0000 I noticed a severe slowdown and network problems on my amd64 -CURRENT system. By bisecting SVN revisions I identified the following commit to be responsible: ---------------------------------------------------------------------- r259045 | kib | 2013-12-06 22:44:13 +0100 (Fri, 06 Dec 2013) | 9 lines Disallow optimizations which potentially remove boundary checks for signed values due to a compiler authors considering integer overflow as impossible. The change follows suit of other projects taking the same measure. ---------------------------------------------------------------------- This commit added the following line to /sys/conf/kern.mk: CFLAGS+= -fno-strict-overflow The most obvious symptoms of the problem on my system are: 1) sa-spamd needs > 140 seconds to start (instead of a few seconds) 2) SSH logins are very slow, many seconds of delay between connect and password prompt, several seconds after password entry until a command prompt appears (normally instantaneous) In general it takes many seconds to open a TCP socket, even to localhost. I can perform further tests on this system, but it will be a lot of work to locate the source files that are mis-compiled with -fno-strict-overflow. I'm surprised that nobody else seems to be affected by this problem, since it is very obvious on my system and clearly caused by the above mentioned commit. My kernel configuration is a stripped down GENERIC plus ZFS, IPFW and LINUX emulation. I can provide full details and a kernel that exposes the problem on request. Regards, STefan