From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [Xenomai-core] xenomai preempting interrupt handler ? From: Philippe Gerum In-Reply-To: <45EFF835.9010305@domain.hid> References: <45EFD796.7050002@domain.hid> <1173346938.17515.16.camel@domain.hid> <45EFE089.9000508@domain.hid> <1173349157.17515.19.camel@domain.hid> <45EFF835.9010305@domain.hid> Content-Type: text/plain Date: Thu, 08 Mar 2007 13:22:41 +0100 Message-Id: <1173356561.17515.26.camel@domain.hid> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: Philippe Gerum Reply-To: rpm@xenomai.org List-Id: "Xenomai life and development \(bug reports, patches, discussions\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Steven Scholz Cc: Xenomai-core@domain.hid On Thu, 2007-03-08 at 12:49 +0100, Steven Scholz wrote: > Philippe, > > >>>> Thus will the duration of the > >>>> ethernet interrupt handler add the the worst case latency? > >>> Not from Linux IRQ handlers; you may want to check this using the > >>> tracer. If hw interrupts are masked there, then it's a blatant bug. > >> How could I check this using the tracer? Small hint please? > > > > http://www.xenomai.org/index.php/I-pipe:Tracer > > "Traces can be generated in many ways. One happens automatically when > CONFIG_IPIPE_TRACE_IRQSOFF is enabled." > > What exactly does that mean? That one trace is generated during boot? > That means that several sources of trace points exist, one of them being controlled by the IRQSOFF switch. MCOUNT cause a trace to be emitted upon each function entry, and so on. > "Another way is to invoke the testsuite, namely latency or irqbench with the > option -f to trigger a freeze on each new maximum latency." > > What exactly does "trigger a freeze" mean? > A snapshot of the current trace log, kept from being overwritten in a separate memory upon freeze, that you can access through /proc/ipipe/trace/frozen. > Steven > -- Philippe.