On 13-04-18 01:11 PM, Mathieu Desnoyers wrote: > * Mathieu Desnoyers ([email protected]) wrote: >> * Alexandre Montplaisir ([email protected]) wrote: >>> On 13-04-18 02:11 AM, Amit Margalit wrote: >>>> Hi, >>>> >>>> Thank for the quick response. Here is the missing data: >>>> >>>> UST >>>> 2.6.32.12-205 (I had to make a tiny patch to make it compile) >>>> MemTotal: 24628852 kB >>>> lttng-ust-2.1.2 >>>> lttng-tools-2.1.1 >>>> lttng-modules-2.1.1 >>>> babeltrace-1.1.0 >>>> userspace-rcu-0.7.6 >>>> >>>> Which patch for 4MB? >>> Hi, >>> >>> Not sure if it's specifically this one that Matthew was talking about, >>> but we have such a patch in the PPA packages. See: >>> http://bazaar.launchpad.net/~lttng/lttng-tools/packaging-daily/view/head:/patches/0002-Increase-default-subbuffer-size-to-4MB.patch >> First, it should be noted that lttng enable-channel allow overriding the >> subbuffer size. >> >> It should be noted that lttng-modules 2.2 is going to output even _more_ >> events, so I don't think just making the buffers larger by default is >> the right approach. > Oh, and I notice that the PPA changes the UST default to 4MB per > subbuffer too. > > That's not going to be pretty for per-pid tracing (which is the default) > on a system with 16 CPUs, tracing 100 processes with UST. 4x4MBx16x100 = > 25600 MB (25GB) of buffers just for UST.
Ok good to know, we will have to update it then. > Messing with defaults in packaging seems odd. Actually, it's a pretty common practice ;) Cheers, Alex > > Mathieu > >> I think we need to port the "loglevel" from UST to lttng-modules ASAP, >> and assign a "debug" loglevel to events we don't care about by default. >> >> Thoughts ? >> >> Thanks, >> >> Mathieu >> >>>> Thanks, >>>> >>>> Amit Margalit >>>> IBM XIV - Storage Reinvented >>>> XIV-NAS Development Team >>>> Tel. 03-689-7774 >>>> Fax. 03-689-7230 >>>> >>>> >>>> >>>> From: Matthew Khouzam <[email protected]> >>>> To: <[email protected]> >>>> Date: 04/15/2013 05:24 PM >>>> Subject: Re: [lttng-dev] Limitations on subbuf_size / num_subbuf? >>>> >>>> >>>> >>>> Not at all a n00b question, but could you give some more info? what is >>>> your version of LTTng tools, are you using UST or kernel tracing? How much >>>> ram is on your system? Kernel version? >>>> >>>> I actually have the patched lttng that has standard subbuffer sizes of 4 >>>> mb, so I have not personnaly seen that problem. But the first thing I >>>> would do is upgrade to the latest stable. >>>> >>>> On 13-04-14 06:49 AM, Amit Margalit wrote: >>>> Hello, >>>> >>>> Sorry for the noob question. I seem to be unable to define the total of >>>> subbuf_size * num_subbuf higher than 4MB. I am getting ~30% discarded >>>> tracepoint data. >>>> >>>> Any assistance would be greatly appreciated. >>>> >>>> Amit Margalit >>>> IBM XIV - Storage Reinvented >>>> XIV-NAS Development Team >>>> Tel. 03-689-7774 >>>> Fax. 03-689-7230 >>> >>> _______________________________________________ >>> lttng-dev mailing list >>> [email protected] >>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev >> -- >> Mathieu Desnoyers >> EfficiOS Inc. >> http://www.efficios.com >> >> _______________________________________________ >> lttng-dev mailing list >> [email protected] >> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
