Re: [ANNOUNCE] 4.4-rc6-rt1
From: Mike Galbraith
Date: Thu Jan 14 2016 - 04:33:30 EST
On Wed, 2016-01-13 at 18:58 +0100, Sebastian Andrzej Siewior wrote:
> * Mike Galbraith | 2016-01-01 08:19:41 [+0100]:
>
> > > PID USER PR NI VIRT RES SHR S %CPU %MEM
> > > TIME+ COMMAND
> > > 3 root -2 0 0 0 0 S 37.3 0.0
> > > 307:52.44 ksoftirqd/0
> > > 32 root -2 0 0 0 0 S 37.3 0.0
> > > 308:08.72 ksoftirqd/2
> > > 42 root -2 0 0 0 0 R 37.3 0.0
> > > 308:32.84 ksoftirqd/3
> > > 22 root -2 0 0 0 0 S 26.9 0.0
> > > 222:29.82 ksoftirqd/1
> > > 1 root 20 0 46628 6980 4976 S 1.3 0.2
> > > 0:13.98 systemd
> > > 22358 williams 20 0 159980 4552 3780 R 1.0 0.1
> > > 0:00.39 top
> >
> > Heh, I didn't notice immediately because I throttle nohz, am seeing
> > only tiny utilization (but nohz idle isn't working). With throttle
> > patch removed, box is screaming, expires=4294990471 pokes eyeball.
>
> This is due to NO_HZ as far as I can tell. My AMD A10 in idle mode
> has
> 0.7% utilisation of ksoftirqd/ with CONFIG_HZ_PERIODIC and with
> CONFIG_NO_HZ_FULL it shows about 25% on all CPU threads.
Thomas said the hrtimer adjustments went a little out of round. I
started rummaging, but then the world woke up from the holidays, so I
didn't get _to_ square one, much lest past it. Hohum.
-Mike