On Mon, 2012-07-16 at 12:02 -0400, Steven Rostedt wrote: > On Mon, 2012-07-16 at 04:02 +0200, Mike Galbraith wrote: > > > > Great, thanks! I got stuck in bug land on Friday. You mentioned > > > performance problems earlier on Saturday, did this improve performance? > > > > Yeah, the read_trylock() seems to improve throughput. That's not > > heavily tested, but it certainly looks like it does. No idea why. > > Ouch, you just turned the rt_read_lock() into a spin lock. If a higher > priority process preempted a lower priority process that holds the same > lock, it will deadlock.
Hm, how, it's doing cpu_chill()? > I'm not sure why you would get a performance benefit from this, as the > mutex used is an adaptive one (failure to acquire the lock will only > sleep if preempted or if the owner is not running). I'm not attached to it, can whack it in a heartbeat.. especially so it the thing can deadlock. I've seen enough of those of late. > We should look at why this performs better (if it really does). Not sure it really does, there's variance, but it looked like it did. -Mike -- 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/
