From: Thomas Gleixner <tglx@linutronix.de>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Clark Williams <williams@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [ANNOUNCE] 4.4-rc6-rt1
Date: Thu, 14 Jan 2016 15:30:05 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.11.1601141528550.3575@nanos> (raw)
In-Reply-To: <1452781751.3460.102.camel@gmail.com>
On Thu, 14 Jan 2016, Mike Galbraith wrote:
> On Thu, 2016-01-14 at 15:17 +0100, Sebastian Andrzej Siewior wrote:
> > * Sebastian Andrzej Siewior | 2016-01-13 18:58:45 [+0100]:
> >
> > > 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.
> >
> > This should fixed it:
> >
> > --- a/kernel/time/timer.c
> > +++ b/kernel/time/timer.c
> > @@ -1453,7 +1453,7 @@ u64 get_next_timer_interrupt(unsigned long
> > basej, u64 basem)
> > * the base lock to check when the next timer is pending and
> > so
> > * we assume the next jiffy.
> > */
> > - return basej;
> > + return basem + TICK_NSEC;
> > #endif
> > spin_lock(&base->lock);
> > if (base->active_timers) {
>
> That's what I had done to stop the screaming interrupt, but box still
> behaved very badly.
If you turn off CONFIG_NO_HZ_FULL and switch to NO_HZ_IDLE is it still bad?
Thanks,
tglx
next prev parent reply other threads:[~2016-01-14 14:32 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-23 22:57 [ANNOUNCE] 4.4-rc6-rt1 Sebastian Andrzej Siewior
2015-12-31 16:24 ` Clark Williams
2016-01-01 7:19 ` Mike Galbraith
2016-01-01 9:14 ` Thomas Gleixner
2016-01-01 9:45 ` Mike Galbraith
[not found] ` <568CF08F.3070001@caviumnetworks.com>
2016-01-13 11:45 ` [ANNOUNCE] 4.4-rc6-rt1 (arm64) Jaggi, Manish
2016-01-13 13:45 ` Sebastian Andrzej Siewior
2016-01-14 11:50 ` Jaggi, Manish
2016-01-13 17:58 ` [ANNOUNCE] 4.4-rc6-rt1 Sebastian Andrzej Siewior
2016-01-13 18:36 ` Grygorii Strashko
2016-01-14 14:59 ` Sebastian Andrzej Siewior
2016-01-14 9:33 ` Mike Galbraith
2016-01-14 14:17 ` Sebastian Andrzej Siewior
2016-01-14 14:29 ` Mike Galbraith
2016-01-14 14:30 ` Thomas Gleixner [this message]
2016-01-14 14:57 ` Mike Galbraith
2016-01-14 15:07 ` Thomas Gleixner
2016-01-14 16:05 ` Mike Galbraith
2016-01-16 13:23 ` Mike Galbraith
2016-01-16 13:43 ` Thomas Gleixner
2016-01-16 13:52 ` Mike Galbraith
2016-01-16 13:59 ` Thomas Gleixner
2016-01-16 14:09 ` Mike Galbraith
2016-01-07 12:15 ` Tim Sander
2016-01-13 13:40 ` Sebastian Andrzej Siewior
2016-01-22 15:35 ` Grygorii Strashko
2016-01-22 15:48 ` Sebastian Andrzej Siewior
2016-01-22 20:44 ` Sebastian Andrzej Siewior
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