Messages in this thread | | | Date | Fri, 28 Mar 2008 11:15:00 +0100 | From | Ingo Molnar <> | Subject | Re: [patch for 2.6.26 0/7] Architecture Independent Markers |
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* KOSAKI Motohiro <m-kosaki@ceres.dti.ne.jp> wrote:
> > text data bss dec hex filename > > 37642 7014 384 45040 aff0 sched.o.before > > 37930 7134 384 45448 b188 sched.o.after > > > > 288 bytes for only 3 markers in the scheduler - that's 96 bytes added > > per every marker (44 bytes of that in the fastpath). > > > > and the tracer codepath is now slower and more complex as well. > > > > A classic lose-lose situation, so let's apply this patch. Not! > > > > NACK-ed-by: Ingo Molnar <mingo@elte.hu> > > I wonder why nobody doesn't fix this serious problem until now. and I > am interesting to what difference to ftrace and marker.
i warned and moaned about it ad nauseum.
furthermore, and because it's Friday again, let me remind folks that SystemTap has an even more significant bloat problem: the fact that it needs a huge download:
Installing: kernel-debuginfo x86_64 2.6.25-0.163.rc7.git1.fc9 development-debuginfo 198 M Installing for dependencies: kernel-debuginfo-common x86_64 2.6.25-0.163.rc7.git1.fc9 development-debuginfo 30 M
Total download size: 229 M
for _every_ updated kernel. That 229 MB size reduces the user base of SystemTap (which is otherwise a totally brilliant and cool tool) to 1% of its potential userbase, to those truly desperate persons who really _need_ to get their problem debugged somehow. But it's nowhere near usable as an easy, ad-hoc kernel instrumentation tool, just due to the sheer size it brings.
for heaven's sake, we can have 3 years of _full Linux kernel history_, with all 87875 commits, with full changelog and dependencies and full source code included, packed into a rather tight, 180 MB git repository ...
[ and then i havent even begun about the on-disk footprint of this monstrum, after the packages have been installed: an additional 850 MB. Puh-lease ... ]
there's a huge disconnect with reality here.
Ingo
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