From owner-freebsd-current@FreeBSD.ORG Sun Dec 15 19:37:03 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 076AE54A for ; Sun, 15 Dec 2013 19:37:03 +0000 (UTC) Received: from nm22-vm0.bullet.mail.ird.yahoo.com (nm22-vm0.bullet.mail.ird.yahoo.com [212.82.109.250]) by mx1.freebsd.org (Postfix) with SMTP id 56FD41CC0 for ; Sun, 15 Dec 2013 19:37:01 +0000 (UTC) Received: from [77.238.189.53] by nm22.bullet.mail.ird.yahoo.com with NNFMP; 15 Dec 2013 19:36:55 -0000 Received: from [46.228.39.97] by tm6.bullet.mail.ird.yahoo.com with NNFMP; 15 Dec 2013 19:36:55 -0000 Received: from [127.0.0.1] by smtp134.mail.ir2.yahoo.com with NNFMP; 15 Dec 2013 19:36:55 -0000 X-Yahoo-Newman-Id: 205499.69707.bm@smtp134.mail.ir2.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: lNqlVeQVM1kjSL2vFSiJkbdZYVNhg1IOz6aXzTuVrDlG0si pMmS6DGtNyX_6L.op3DECuZ8dZzFnYTLRaK9hrSFwk0SkXAenpoit4sCfO1w np0coN5bkSNVXQOkejpAyff3BVbfmehIUayeidVoqtIX7nXcKzbMms0Gktaz Zc3830AfveOprsv5LocMc_nyfTpfenAn8p4c2v2KyrW0pc2NwceFT8q.VG2A AfvOoT4P63N2Becxxs8oT7LFl9vowsB9e9uch_TREFwZ5vd8tq7SXcNYwEd6 ehw8duYbK3d6K6UUPXzQWRg.x9nYeqV.OGiVhYF8fwc.YRc6BgXSeP_ICFxx 6D33VmWbbsMekSc7m.PkGAVyGjCvAAcrqKZc4XUi6Et705BWbctEPoHEM0a0 NqBcCnEi0bxhjtbFCEj88B3QXpXr3SfYcbSa46uLfe8Iwqmi9oTxufVEU9or CHvdsxxmMU4rtauB88uzgsuvGkaYZ48ihL0zza_uKSBuDSxc88UhdbdZFLIS KEYmBRsAnCC69jdWsBU1IcQnSdEDf X-Yahoo-SMTP: iDf2N9.swBDAhYEh7VHfpgq0lnq. X-Rocket-Received: from [192.168.119.11] (se@84.154.124.218 with plain [188.125.69.59]) by smtp134.mail.ir2.yahoo.com with SMTP; 15 Dec 2013 19:36:55 +0000 UTC Message-ID: <52AE04D6.9000205@freebsd.org> Date: Sun, 15 Dec 2013 20:36:54 +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: Steven Hartland , Konstantin Belousov , Steve Kargl Subject: Re: SVN commit 259045 breaks -CURRENT References: <52ACD12A.5020906@freebsd.org> <20131214215904.GA24545@troutmask.apl.washington.edu> <52ACD783.7030203@freebsd.org> <20131214221627.GA24637@troutmask.apl.washington.edu> <20131215054722.GI59496@kib.kiev.ua> <52ADADAD.1010108@freebsd.org> <80611904E98F4481B2E7088350321199@multiplay.co.uk> In-Reply-To: <80611904E98F4481B2E7088350321199@multiplay.co.uk> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-current@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: Sun, 15 Dec 2013 19:37:03 -0000 Am 15.12.2013 17:27, schrieb Steven Hartland: > > ----- Original Message ----- From: "Stefan Esser" > To: "Konstantin Belousov" ; "Steve Kargl" > > Cc: > Sent: Sunday, December 15, 2013 1:25 PM > Subject: Re: SVN commit 259045 breaks -CURRENT > > >> Am 15.12.2013 06:47, schrieb Konstantin Belousov: >>> On Sat, Dec 14, 2013 at 02:16:27PM -0800, Steve Kargl wrote: >>>> On Sat, Dec 14, 2013 at 11:11:15PM +0100, Stefan Esser wrote: >>>>> Am 14.12.2013 22:59, schrieb Steve Kargl: >>>>>> On Sat, Dec 14, 2013 at 10:44:10PM +0100, Stefan Esser >>>>>> wrote: >>>>>>> >>>>>>> 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) >>>>>>> >>>>>> >>>>>> Ah, so that explains the behavior I'm see. Just updated a >>>>>> circa Aug 3rd i386 FreeBSD to top-of-tree. My ssh logins to >>>>>> my work system take 30+ seconds now. :( >>>>> >>>>> You may want to test the attached patch, which reverts the >>>>> above mentioned commit. >>>>> >>>> >>>> I probably won't get to it until tomorrow, because I had started a >>>> dog-food system purge including re-installing all ports. The laptop >>>> takes a bit a time to recompile everything. >>>> >>> >>> Are you all running i386, compiled with gcc ? >> >> I'm on -CURRENT, CLANG, amd64. But since the problem has also been >> reported for i386 compiled with GCC, there seems to be some problem >> in common kernel code, that has been uncovered by your change, >> >> BTW: I remember seeing two wait channels being reported when I type >> ^T during multi-user startup (sa-spamd, which needs 140 seconds with >> the broken kernel: >> >> nanosleep >> kqueue (I do not remember whether this name is exact or abbreviated) >> >> I've been assuming that the problem might actually be in nanosleep(), >> since this is a timing related function and we are seeing huge >> delays, but eventually the delayed action succeeds. >> >> But a kernel with only kern_conf.c compiled with -fno-strict-overflow >> did not show the delays. I do not have time for further tests, today. > > Delay in ssh login for ~30 is typical if its failing to resolve > the connecting IP. The update didn't break your resolver in anyway > did it? No, I see a delay of some 3 to 5 seconds between start of the client and password prompt and another delay of 3 to 10 seconds after password entry and login prompt. There is no observable delay with a non-broken kernel. It was not me who reported 30s+ delays for SSH logins. And the delays exist even if connecting to the local SMTP port (e.g. a telnet localhost 25 takes a few seconds to establish the connection). (I had to disable VerifyHostKeyDNS in my SSH client, to prevent a 30s delay on outgoing connections. But this is completely unrelated.) Regards, STefan