From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1Js1Np-0003j1-SU for user-mode-linux-devel@lists.sourceforge.net; Fri, 02 May 2008 12:57:29 -0700 Received: from saraswathi.solana.com ([198.99.130.12]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1Js1No-0003ke-DG for user-mode-linux-devel@lists.sourceforge.net; Fri, 02 May 2008 12:57:29 -0700 Date: Fri, 2 May 2008 15:57:20 -0400 From: Jeff Dike Message-ID: <20080502195720.GB10369@c2.user-mode-linux.org> References: <877iel7ljp.fsf@hades.wkstn.nix> <87ve256146.fsf@hades.wkstn.nix> <871w4sqxgv.fsf@hades.wkstn.nix> <20080428164443.GB9628@c2.user-mode-linux.org> <871w4n9fo8.fsf@hades.wkstn.nix> <20080501151351.GA6303@c2.user-mode-linux.org> <87prs57g4h.fsf@hades.wkstn.nix> <20080502163020.GB7843@c2.user-mode-linux.org> <87bq3o5yeo.fsf@hades.wkstn.nix> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <87bq3o5yeo.fsf@hades.wkstn.nix> Subject: Re: [uml-devel] actually useful backtrace from a CPU-chewing hang List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Nix Cc: user-mode-linux-devel@lists.sourceforge.net On Fri, May 02, 2008 at 07:55:11PM +0100, Nix wrote: > No behavioural change :( Oh well. > I'm trying something else now, arranging for os_nsecs() itself to do the > never-backwards stuff on the assumption that something depends on > monotonic timers not skipping backwards which presently they might > (there are callers of os_nsecs() outside of os-Linux/time.c, notably in > kernel/time.c, and currently they see an unadjusted time, jumping > backwards and forwards and whatever). This sounds like a reasonable idea. Another thing you might try is the following: get two extra windows in one, get a "strace -p uml-pid -o strace.out -tt" ready in two, get a "date ; sudo date -s "now-5 sec" ; date" ready hit return in one, then in two, then in your UML window when the UML gives you another prompt (or you've decided it's hung), ^C the strace Look at the times reported by the dates, find the time change in the strace log, and send the section following that (and a bit before) to me. Jeff -- Work email - jdike at linux dot intel dot com ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel