On Fri, 8 Aug 2014 18:01:28 +0200 Peter Zijlstra <pet...@infradead.org> wrote:
> Well, see the _BIG_ difference is that currently, when I do nop > > current_tracer all that memory is instantly freed again. > > With the proposed scheme, if I setup state, reconsider, destroy state, > try again, and generally muck about I can tie up unspecified amounts of > memory. > > And being the bumbling idiot that I am, that's actually fairly typical > of how I end up tracing. There's no neat and tidy, I trace something, > look at the trace, script a little, muck about with the settings and > goto 1. It would actually be trivial to make that case never free the trampoline associated to function tracing. As that is a static ops that never gets freed, the trampoline it uses doesn't need to be freed either. But, if you were to do: # cd /sys/kernel/debug/tracing # mkdir instances/foo # cd instances/foo 1: # echo function > current_tracer # echo nop > current_tracer goto 1 Then, yeah that could do it. > > > In any case, I think I now fully understand what you're trying to do, > just not sure its all win. Fair enough. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
