From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <512FB9B5.9040709@xenomai.org> Date: Thu, 28 Feb 2013 21:10:29 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Xenomai-forge: thread using 100% cpu load List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ronny Meeus Cc: xenomai@xenomai.org On 02/28/2013 08:19 PM, Ronny Meeus wrote: > Hello > > we are using the PSOS interface of Xenomai forge, running completely > in user-space using the mercury code. > We deploy our application on different processors, one product is > running on PPC multicore (P4040, P4080, P4034) and another one on > Cavium (8 core device). > The Linux version we use is 2.6.32 but I would assume that this is not > so relevant. > > Our Xenomai application is running on one of the cores (affinity is > set), while the other cores are running other code. > > On both architectures we recently start to see issues that one thread > is consuming 100% of the core on which the application is pinned. > The thread that monopolizes the core is the thread internally used to > manage the timers, running at the highest priority. > The trigger for running into this behavior is currently unclear. > If we only start a part of the application (platform management only), > the issue is not observed. > We see this on both an old version of Xenomai and a very recent one > (pulled from the git repo yesterday). > > I will continue to debug this issue in the coming days and try isolate > the code that is triggering it, but I can use hints from the > community. > Debugging is complex since once the load starts, the debugger is not > reacting anymore. > If I put breakpoints in the functions that are called when the timer > expires (both oneshot and periodic), the process starts to clone > itself and I endup with tens of them. > > Has anybody seen an issue like this before or does somebody has some > hints on how to debug this problem? First enable the watchdog. It will send a signal to the application when detecting a problem, then you can use the watchdog to trigger an I-pipe tracer trace when the bug happens. You will probably have to increase the watchdog polling frequency, in order to have a meaningful trace. -- Gilles.