From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24403 invoked from network); 17 Apr 2007 10:05:24 -0000 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,FORGED_RCVD_HELO autolearn=ham version=3.1.8 Received: from news.dotsrc.org (HELO a.mx.sunsite.dk) (130.225.247.88) by ns1.primenet.com.au with SMTP; 17 Apr 2007 10:05:24 -0000 Received-SPF: none (ns1.primenet.com.au: domain at sunsite.dk does not designate permitted sender hosts) Received: (qmail 36626 invoked from network); 17 Apr 2007 10:05:17 -0000 Received: from sunsite.dk (130.225.247.90) by a.mx.sunsite.dk with SMTP; 17 Apr 2007 10:05:17 -0000 Received: (qmail 15914 invoked by alias); 17 Apr 2007 10:05:14 -0000 Mailing-List: contact zsh-workers-help@sunsite.dk; run by ezmlm Precedence: bulk X-No-Archive: yes X-Seq: 23284 Received: (qmail 15904 invoked from network); 17 Apr 2007 10:05:13 -0000 Received: from news.dotsrc.org (HELO a.mx.sunsite.dk) (130.225.247.88) by sunsite.dk with SMTP; 17 Apr 2007 10:05:13 -0000 Received: (qmail 36270 invoked from network); 17 Apr 2007 10:05:13 -0000 Received: from flpi101.sbcis.sbc.com (207.115.20.70) by a.mx.sunsite.dk with SMTP; 17 Apr 2007 10:05:10 -0000 X-ORBL: [76.211.249.141] Received: from [76.211.249.141] (adsl-76-211-249-141.dsl.pltn13.sbcglobal.net [76.211.249.141]) by flpi101.sbcis.sbc.com (8.13.8 out.dk.spool/8.13.8) with ESMTP id l3HA48q0000384; Tue, 17 Apr 2007 03:04:11 -0700 Message-ID: <46249BC7.8070200@cowan.name> Date: Tue, 17 Apr 2007 03:04:55 -0700 From: Micah Cowan User-Agent: Thunderbird 1.5.0.10 (X11/20070403) MIME-Version: 1.0 To: davidpeer@cs.huji.ac.il, zsh-workers@sunsite.dk Subject: Re: Bug in ulimit ? References: <46248CC2.4010901@cs.huji.ac.il> <462493C0.20700@cowan.name> <20070417094244.GA4955@sc.homeunix.net> In-Reply-To: <20070417094244.GA4955@sc.homeunix.net> X-Enigmail-Version: 0.94.2.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Stephane Chazelas wrote: > On Tue, Apr 17, 2007 at 02:30:40AM -0700, Micah Cowan wrote: >> David Peer wrote: >>> If the user run: ulimit -t 0, he can run jobs without any cputime >>> limitation: >> This sounds more like a kernel problem to me than a zsh bug. I get the >> same behavior on my Ubuntu 7.04 (beta) system, in _bash_. >> >> I note that getrlimit(2) says: >> >> In 2.6.x kernels before 2.6.17, a RLIMIT_CPU limit of 0 is wrongly >> treated as "no limit" (like RLIM_INFINITY). Since kernel 2.6.17, set??? >> ting a limit of 0 does have an effect, but is actually treated as a >> limit of 1 second. >> >> However, I'm running 2.6.20(-14-generic), and still experiencing that >> symptom. > [...] > > (note that there's a lot a modern CPU can do in 1 second). > > Works as I'd expect from your man page quote here: > > $ time zsh -c 'ulimit -t 0; while :; do :; done' > zsh: cpu limit exceeded zsh -c 'ulimit -t 0; while :; do :; done' > zsh -c 'ulimit -t 0; while :; do :; done' 0.72s user 0.28s system 95% cpu 1.050 total > $ time bash -c 'ulimit -t 0; while :; do :; done' > zsh: killed bash -c 'ulimit -t 0; while :; do :; done' > bash -c 'ulimit -t 0; while :; do :; done' 1.00s user 0.00s system 95% cpu 1.047 total > $ uname -a > Linux sc.homeunix.net 2.6.21-rc4 #1 PREEMPT Sun Mar 25 15:39:31 BST 2007 i686 GNU/Linux > ~$ uname -rs > Linux 2.6.21-rc4 Yes, I get those same results. However, in an interactive shell: % ulimit -t 0 % ( ulimit -t; while :; do :; done ) 0 << watch the CPU time used climb in top >> ^C % ... % ulimit -Ht 0 % ( ulimit -t; while :; do :; done ) 0 zsh: killed (; ulimit -t; while :; do; :; done; ) % My first thought was: is zsh blocking SIGXCPU in some circumstances? But killing the process with kill -XCPU worked fine. It therefore appears that while the manpage is correct for hard limits, soft limits of 0 are still treated as unlimited. -- Micah J. Cowan Programmer, musician, typesetting enthusiast, gamer... http://micah.cowan.name/