From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Yukg6-0001Df-Fs for user-mode-linux-devel@lists.sourceforge.net; Tue, 19 May 2015 16:47:38 +0000 Received: from ivanoab4.miniserver.com ([78.31.104.92]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1Yukg5-0005kK-HB for user-mode-linux-devel@lists.sourceforge.net; Tue, 19 May 2015 16:47:38 +0000 Message-ID: <555B691C.2010303@kot-begemot.co.uk> Date: Tue, 19 May 2015 17:47:24 +0100 From: Anton Ivanov MIME-Version: 1.0 References: <1431854739.603436.45.camel@m3y3r.de> <555B62A9.9000902@kot-begemot.co.uk> In-Reply-To: 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 Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net Subject: Re: [uml-devel] [PATCH] um: Switch clocksource to hrtimers To: Richard Weinberger Cc: "user-mode-linux-devel@lists.sourceforge.net" On 19/05/15 17:39, Richard Weinberger wrote: > On Tue, May 19, 2015 at 6:19 PM, Anton Ivanov > wrote: >> Same story. >> >> Overall works quite well, the moment I give it the "dselect upgrade >> test" the userspace hangs. >> >> Kernel continues to work - forwarding, icmp, uml_mconsole are fine. > Do you know where it hangs? > Maybe the kernel does not get any scheduler tick and does not schedule a task.., Kernel continues to get ticks, timers increment, io also works. If I strace the kernel I see a mix of SIGALRM (or in the oder version -USR2), SIGIO and SIGCHLD. Nothing out of the ordinary. Uml mconsole works. I cannot get meaningful information because trying to invoke backtraces I get "SIGSEGV in SIGSEGV handler" for all processes. Memory looks OK too - 500MB+ free on a 1GB UML. Syncronous vs asynchronous FS does not change it so it is not a variety of the writeout bug. If I could get a bt for the userspace task and/or its stub we could have nailed it. I suspect it is spinning in skas/process.c for some reason. No idea why, but it takes 100% CPU. A. > ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel