----- Original Message ----- > From: "Corey Minyard" <[email protected]> > To: "David Goulet" <[email protected]> > Cc: [email protected] > Sent: Tuesday, January 14, 2014 3:39:43 PM > Subject: Re: [lttng-dev] Extract lttng trace from kernel coredump > > On 01/14/2014 12:42 PM, David Goulet wrote: > > On 13 Jan (16:39:47), Corey Minyard wrote: > >> I'm working on a feature to allow an lttng trace to be extracted from a > >> kernel coredump, and I'm wondering the best way to proceed. I've looked > >> at extracting from the existing data structures, but that would require > >> something to always have a trace file open and it looks more than a > >> little complicated. I was thinking instead of having a different trace > >> channel for configuring this coredump and some globals to point to the > >> various data structures. Would that be the best way to pursue this? Is > >> there a better way, perhaps? > > Oh yes we do actually already have a way to do that :) > > > > Please see: > > https://git.lttng.org/?p=lttng-tools.git;a=tree;f=extras/core-handler;h=29ded89a71fd36e159d671ca1f405cea394f8683;hb=HEAD > > > > With the snapshot feature, it's quite easy to do that. Hope that helps > > you with what you are trying to achieve. > > I did see that, but it seems to be for an application coredump. I was > looking for something that would work for a kernel coredump. So that if > the kernel crashes, you can use kdump to extract the kernel core and > then extract the LTT buffers from that. The idea is that if the kernel > crashes, you can get some idea of what was happening before the crash.
Something along these lines have been proposed a while back on the ML, but it was against an old LTTng version (0.x): http://lists.lttng.org/pipermail/lttng-dev/2010-August/014239.html It might be interesting to adapt it to the newer LTTng 2.x. Anyone interested to look into this ? Thanks, Mathieu > > > Thanks, > > -corey > > > Cheers! > > David > > > >> Thanks, > >> > >> -corey > >> > >> _______________________________________________ > >> 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 > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
