I've have some patch to make LTTng 2.0 works on a 2.6.32 kernel. I'll post that soon...
On Wed, Nov 23, 2011 at 12:53 PM, Abhishek Karoliya <[email protected]> wrote: > Thanks Mathieu for the pointers... > > I have got a half cooked third party kernel when it comes to lttng > patches which is making it harder than it has to get to the code. The > kernel has been applied with Lttng patches but no one knows which > version of the patch reside. Off target but it will be immense help is > you or anyone could give help me deduce what kernel patch version has > been applied. What files or strings I could search? It is a 2.6.34 > kernel with pre-empt rt patch. > > I am all for 2.0 but the program here hasn't progressed to 2.6.35 and > it will be some time before we will start using it. > > On Tue, Nov 22, 2011 at 11:50 AM, Mathieu Desnoyers > <[email protected]> wrote: >> * Abhishek Karoliya ([email protected]) wrote: >>> Hello People, >>> >>> I am using LTTng to get around a scheduling and priority inheritance >>> problem that we are observing on our system (powerpc e500v2 dual core, >>> linux 2.6.34). However, I need map timestamps for events as seen in >>> Lttng trace, kernel and application (I am using TSC divided by time >>> base freq for application). I see that even though stop tracing >>> (lttctl -D ) at 601.xxxxxx (/var/log/kernel ) >>> Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ 601.695548] LTT: 284 events >>> written in channel metadata (cpu 1, index 0) >>> Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ 601.710868] LTT: 40 events >>> written in channel module_state (cpu 1, index 0) >>> ............................................... >>> Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ 601.710978] LTT: 32 events >>> written in channel softirq_state (cpu 1, index 0) >>> >>> When I look dump the trace using lttv, I can see events that are >>> timestamped upto 670.xxxxxxxx. >>> >>> I am wondering if this is due some timing offset? If yes, how could I >>> match them? >>> >>> My Setup >>> ltt-control-0.89-05122011 >>> lttv-0.12.36-18112010 >>> linux-2.6.32 with pre-empt RT patch >>> >>> Any pointers will be greatly appreciated. >> >> The LTTng timestamps, on powerpc, are directly derived from the TB >> register value, without offset. The timestamp used in printk logs is >> based, if my memory serves me correctly, on the kernel monotonic clock. >> You might want to check what offset they apply to this clock, or try to >> record the data from userspace through the marker_event (was theat even >> the exact name, not sure anymore) debugfs file exposed by lttng through >> debugfs. It's also possible that the printk timestamps are based on the >> current time of day, which is offset by the ntp-correction. >> >> Or you can try lttng 2.0. It comes with kernel and user-level tracing. >> For the moment, it uses the CLOCK_MONOTONIC clock source both both >> kernel and user-level tracing (until we reimplement the trace clocks >> into lttng 2.0 and the vDSOs for userspace LTTng-UST). We also have the >> dynamic task priority and nice level that we can record along with >> events (see lttng add-context), which will be tremendously useful to >> debug the kind of priority inversion problem you are investigating. >> >> However, you need a kernel version >= 2.6.35 to build the lttng-modules. >> No kernel patches are required (it's just a module package). >> >> For more info, see http://lttng.org/lttng2.0 >> >> Best regards, >> >> Mathieu >> >> >>> >>> Thanks >>> Abhi >>> >>> _______________________________________________ >>> ltt-dev mailing list >>> [email protected] >>> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev >>> >> >> -- >> Mathieu Desnoyers >> Operating System Efficiency R&D Consultant >> EfficiOS Inc. >> http://www.efficios.com >> > > _______________________________________________ > ltt-dev mailing list > [email protected] > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > -- Yannick Brosseau www.projetmontreal.org Consultant en logiciel libre yannickbrosseau.com _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
