From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <521871FD.30705@web.de> Date: Sat, 24 Aug 2013 10:42:37 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <5215C4FE.707@inmess.de> In-Reply-To: <5215C4FE.707@inmess.de> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Subject: Re: [Xenomai] two dd processes: soft lockup List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Benedikt Boeck Cc: xenomai@xenomai.org On 2013-08-22 09:59, Benedikt Boeck wrote: > Hello, > = > I got a problem. After starting two dd processes (if=3D/dev/zero > of=3D/dev/null), I get first a few messages about soft lockup: > kernel:[...] BUG: soft lockup - CPU#. stuck for ..s! [dd:...] > and little later a > Kernel panic - not syncing: Fatal exception in interrupt > = > But if I had running xeno-test before and then starting two dd processes > I don't get a soft lockup. Strange? > = > Also there is no soft lockup with a kernel identical till a deactivated > CONFIG_XENOMAI. > A deactivated CONFIG_SMP also prevent the error. But I like to have both > cores. Trying all four variants of CONFIG_SCHED_SMT=3Dy/n and > CONFIG_SCHED_MC=3Dy/n didn't effect the error. > = > Tested with different kernel versions (3.4.6, 3.5.7, 3.8) always with > matching ipipe patch. I think with 3.8 I didn't get a kernel panic but > still soft lockups. > Using Xenomai 2.6.2.1 and haven't tried other versions yet. The > processor is a Celeron Dual-Core T3100. > = > Does somebody have a idea? Maybe I just made a simple (but effective) > mistake. I've tried your configuration on ipipe-3.8 [1] but wasn't able to reproduced it in a 2-cpu VM with 2 dd instances. Could you provide the 3.8 config as well that generates the warnings for you? And please provide the information Gilles asked for, Thanks, Jan [1] http://git.xenomai.org/?p=3Dipipe.git;a=3Dshortlog;h=3Drefs/heads/ipipe= -3.8 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 263 bytes Desc: OpenPGP digital signature URL: