On Thu, Jul 25, 2013 at 06:16:32PM +0300, Andriy Gapon wrote: > on 22/07/2013 05:28 [email protected] said the following: > > http://people.freebsd.org/~markj/patches/sdt-module-info/20130721-sdt-module-info.diff > > Mark, > > this is a minor suggestion only partially related to your patch. > I think that it would be nice if module loading and unloading events were > posted > via EVENTHANDLER(9) mechanism. Then instead of introducing yet more DTrace > related hooks in the kernel code, DTrace modules could just subscribe to those > events. Also, those events could be potentially useful to other consumers > beyond DTrace. > What do you think?
Hm, now that I look at this, I'm not sure if it can work. The unload hooks need to be able to veto a module unload in the case that one of its probes is enabled. This is done by checking whether lf->nenabled > 0, and it needs to be done with the dtrace lock held to prevent races. I've done this by having the unload hooks return a non-zero value if there are probes enabled, but EVENTHANDLER(9) doesn't give me a way to look at a handler's return value. Do you see a way to get around this? Thanks, -Mark _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-dtrace To unsubscribe, send any mail to "[email protected]"
