I expect we could let an environment variable control this. I would be tempted to make the default behavior switch to the new user ID buffers in the future though, for security reasons.
Thoughts ? Thanks, Mathieu * Amit Margalit ([email protected]) wrote: > This (current) behavior you describe is very suitable for our needs. > > Is there an intention to insert a hook into setuid() in the future? > If yes - will the existing behavior remain as a default and the hook be > used only if I choose to use it? > > Thanks, > > Amit Margalit > IBM XIV - Storage Reinvented > XIV-NAS Development Team > Tel. 03-689-7774 > Fax. 03-689-7230 > > > > From: Mathieu Desnoyers <[email protected]> > To: Amit Margalit/Israel/IBM@IBMIL > Cc: Michel Dagenais <[email protected]>, > [email protected] > Date: 04/29/2013 07:27 PM > Subject: Re: [lttng-dev] Is there a way to make LTTng use the same > subbuffers for multiple processes? > > > > * Amit Margalit ([email protected]) wrote: > > Another 2.2 question - > > > > What if I have a single process, that forks, and each child process then > > > changes its own UID. Will the tracing continue on the parent UID > buffers? > > Yes, we indeed currently keep the user ID that was effective at process > creation or last exec() encountered, because we don't have hooks in > libc's setuid() at the moment. > > Thanks, > > Mathieu > > > > > Thanks, > > > > Amit Margalit > > IBM XIV - Storage Reinvented > > XIV-NAS Development Team > > Tel. 03-689-7774 > > Fax. 03-689-7230 > > > > > > > > From: Michel Dagenais <[email protected]> > > To: Amit Margalit/Israel/IBM@IBMIL > > Cc: [email protected] > > Date: 04/29/2013 04:32 AM > > Subject: Re: [lttng-dev] Is there a way to make LTTng use the > same > > subbuffers for multiple processes? > > > > > > > > > > > Our system is a 12-core x86 (6-core + HT). If I take 4 subbuffers of > > 1MB, this means 4MB per > > > process. As the number of processes rises, this becomes prohibitive. > > > For example, we may need to support > 500 sub-processes ==> 500 * 4MB > = > > 2GB - > > > which is a bit too much. Is there a way to tell LTTng to share the > > sub-buffers with forked processes? > > > > This is the number one feature listed in the changelog for lttng-tools > and > > UST for version 2.2. The first release candidate is out so you can try > the > > feature, and the final 2.2 version should not be too far away. > > > > http://lttng.org/lttng-tools-220-rc1 > > - Add UST per UID buffers support > > > > > _______________________________________________ > > lttng-dev mailing list > > [email protected] > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com > > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
