Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932531AbVI3BAJ (ORCPT ); Thu, 29 Sep 2005 21:00:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932534AbVI3BAI (ORCPT ); Thu, 29 Sep 2005 21:00:08 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.142]:44955 "EHLO e2.ny.us.ibm.com") by vger.kernel.org with ESMTP id S932531AbVI3BAG (ORCPT ); Thu, 29 Sep 2005 21:00:06 -0400 Date: Thu, 29 Sep 2005 18:00:41 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Gleixner , Steven Rostedt , Jeff Dike Subject: Re: 2.6.13-rc6-rt9 Message-ID: <20050930010041.GS8177@us.ibm.com> Reply-To: paulmck@us.ibm.com References: <20050818060126.GA13152@elte.hu> <1124470574.17311.4.camel@twins> <1124476205.17311.8.camel@twins> <20050819184334.GG1298@us.ibm.com> <1124566045.17311.11.camel@twins> <20050820212446.GA9822@ccure.user-mode-linux.org> <1127980463.14695.6.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1127980463.14695.6.camel@twins> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1917 Lines: 73 On Thu, Sep 29, 2005 at 09:54:23AM +0200, Peter Zijlstra wrote: > On Sat, 2005-08-20 at 17:24 -0400, Jeff Dike wrote: > > On Sat, Aug 20, 2005 at 09:27:25PM +0200, Peter Zijlstra wrote: > > > Jeff, could you help us out here? > > > What exactly does uml need to get out of the calibrate delay loop? > > > > Interrupts, it's not too demanding :-) > > > > If it's not seeing VTALRM, then it will never leave the calibration loop. > > > > Try stracing it and see what it's getting. > > Sorry for the late reply. > > Yes, that does seem to be the problem. > > Even with a current -rt (2.6.14-rc2-rt5) UML does not run. The issue is > indeed (as jeff pointed out) that VTALRM is never send. The small test > programm below illustrates this. > > On a non-rt kernel it completed in 1 second. > On a -rt kernel it waits at infinitum. Will play with it and see what I broke... Thanx, Paul > Kind regards, > > Peter Zijlstra > > --------------------------- > > #include > #include > #include > #include > #include > > volatile int quit = 0; > > void sig_vtalrm(int signr, siginfo_t * si, void * arg) > { > if (signr == SIGVTALRM) quit = 1; > } > > int main() > { > struct itimerval ival = {{0,0}, {1, 0}}; > > struct sigaction sa; > sa.sa_sigaction = sig_vtalrm; > sigemptyset(&sa.sa_mask); > sa.sa_flags = 0; > sigaction(SIGVTALRM, &sa, NULL); > > setitimer(ITIMER_VIRTUAL, &ival, NULL); > > printf("wait\n"); > while (!quit) ; > printf("done\n"); > } > > > -- > Peter Zijlstra > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/