Re: [PATCH] fix __mod_timer vs __run_timers deadlock.

Zwane Mwaikambo
2005-05-03T01:32:50Z

On Mon, 2 May 2005, Lee Revell wrote:

> On Tue, 2005-05-03 at 10:13 +1000, Benjamin Herrenschmidt wrote:
> > Well, there may be other issues brought by this new timer code though.
> > I'm running G5s regulary without a lockup or anything for weeks, so it
> > would be interesting if you could try to find out what's involved in
> > that other lockup you had.
>
> It seems like it would not be to hard to create a timer test suite that
> just hammers the timer subsystem, creating and deleting and modifying
> zillions of timers, changing the system time, etc. Combined with
> running with HZ=10000 or something it seems like you could shake out
> bugs a lot faster than just running & waiting for a race to show up.
>
> I've seen timer related issues (the set_rtc_mmss issue that George
> Anzinger fixed) while testing the RT patchset that I could only ever
> reproduce once.

Heavy networking load should do it, something like volanomark actually
does quite a decent job of stressing timers.