On Tue, 06 Jul 2010 19:49:47 -0400 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > On Tue, 2010-07-06 at 16:12 -0700, Andrew Morton wrote: > > > Well if we're so worried about resource wastage then how about making > > all boot-time-only text and data reside in __init and __initdata > > sections rather than hanging around uselessly in memory for ever? > > That would be a patch I would like :-) > > I could probably do that when I get some time. > > > > > Only that's going to be hard because we went and added pointers into > > .init.text from .data due to `struct tracer.selftest', which will cause > > a storm of section mismatch warnings. Doh, should have invoked the > > selftests from initcalls. That might open the opportunity of running > > the selftests by modprobing the selftest module, too. > > They are called by initcalls. The initcalls register the tracers and > that is the time we call the selftest. No other time. It should all be __init! > Is there a way that we set up a function pointer to let the section > checks know that it is only called at bootup? <sticks his nose in modpost.c for the first time> There are various whitelisting hacks in there based on the name of the offending symbol. Search term: DEFAULT_SYMBOL_WHITE_LIST. It'd be cleaner to just zap the tracer.selftest field altogether and run the tests from initcalls if possible? > > > > And I _do_ wish the selftest module was modprobeable, rather than this > > monstrosity: > > The selftests are done by individual tracers at boot up. It would be > hard to modprobe them at that time. No, if tracer_selftest.o was linked into vmlinux then the tests get run within do_initcalls(). If tracer_selftest.o is a module, then the tests get run at modprobe-time. The latter option may not be terribly useful but it comes basically for free as a reward for doing stuff correctly. > > > #ifdef CONFIG_FTRACE_SELFTEST > > /* Let selftest have access to static functions in this file */ > > #include "trace_selftest.c" > > #endif > > > > Really? Who had a tastebudectomy over there? At least call it > > trace_selftest.inc or something, so poor schmucks don't go scrabbling > > around wondering "how the hell does this thing get built oh no they > > didn't really go and #include it did they?" > > > Well this is also the way sched.c adds all its extra code. The sched.c hack sucks too. > Making it > trace_selftest.inc would make it hard to know what the hell it was. trace_selftest.i_really_suck? > And > also hard for editors to know what type of file it is, or things can be > missed with a 'find . -name "*.[ch]" | xargs grep blahblah' Well bad luck. Of _course_ it makes a mess. It's already a mess. How's about just removing the `static' from whichever symbols tracer_selftest needs? That'd surely be better than #including a .c file. > Yes, the self tests are ugly and can probably go with an overhaul. Since > we are trying to get away from the tracer plugins anyway, they will > start disappearing when the plugins do. > > We should have some main selftests anyway. Those are for the TRACE_EVENT > tests (which are not even in the trace_selftest.c file, and the function > testing which currently are, as well as the latency testers. > > The trace_selftest.c should eventually be replaced with more compact > tests for the specific types of tracing. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>