On Mon, 2011-09-12 at 09:33 +0200, Thomas Gleixner wrote: > On Sun, 11 Sep 2011, Mike Galbraith wrote: > > > I'm very definitely missing sirq threads from the wakeup latency POV. > > > > (Other things are muddying the water, eg. rcu boost, if wired up and > > selected always ramming boosted threads through the roof instead of > > configured boost prio.. etc etc, but this definitely improves my latency > > woes a lot) > > > > This is a giant step backward from "let's improve abysmal throughput", > > so I'm wondering if anyone has better ideas. > > One of the problems we have are the signal based timers (posix-timer, > itimer). That's the biggest part of my jitter troubles. > We really want to move the penalty for those into the context > of the thread/process to which those timers belong. The trick is to > just note the expiry of a timer and wake up the target which has to > deal with the real work in his own context and on his own > account. That's rather simple for thread bound signals, but has a lot > of implications with process wide ones. Though it should be doable and > I'd rather see that solved than hacking around with the split softirqs That definitely sounds like a better idea.. for someone who thoroughly understands signals. > > WRT below: "fixes" are dinky, this is not... > > > > sched, rt, sirq: resurrect sirq threads for RT_FULL > > > > Not-signed-off-by: Mike Galbraith <efault@xxxxxx> > > Not-that-delighted: tglx Ditto. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
