Re: rcu_preempt running flat out on idle desktop.
From: Dave Jones
Date: Thu Jun 06 2013 - 11:32:31 EST
On Tue, May 14, 2013 at 03:21:07AM +0200, Frederic Weisbecker wrote:
> On Thu, May 09, 2013 at 05:10:26PM -0400, Dave Jones wrote:
> > On Thu, May 09, 2013 at 11:02:08PM +0200, Frederic Weisbecker wrote:
> >
> > > > RCU options for this build are..
> > > >
> > > I can't reproduce that issue even with the above setting. Could you
> > > please send me your whole config?
> >
> > http://paste.fedoraproject.org/11363/36813375/raw/
>
> Sorry it took me some time to get that config booting, I ran into
> other unrelated crashes.
>
> So I'm observing the exact opposite than you: the processes appear to
> have no load nor to consume cputime. Even if I use some dumb user loop.
> Top don't even show it.
>
> I'm digging further and will tell you when I get more info.
So I'm still seeing this on rc4.
Here's my 'idle' firewall, just routing packets:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4405 root 20 0 0 0 0 S 400.0 0.0 52336:27 kworker/2:0
20968 davej 20 0 115m 1840 1092 R 400.0 0.1 2297:48 top
964 named 20 0 383m 32m 2896 S 400.0 1.7 81384:54 named
10 root 20 0 0 0 0 S 400.0 0.0 195403:05 rcu_preempt
20830 davej 20 0 125m 2172 1024 S 400.0 0.1 939:36.10 sshd
11 root 20 0 0 0 0 S 400.0 0.0 42644:33 rcuop/0
13 root 20 0 0 0 0 S 400.0 0.0 34729:04 rcuop/2
754 lighttpd 20 0 54640 2692 1732 S 400.0 0.1 35286:11 lighttpd
756 root 20 0 216m 10m 6116 S 400.0 0.5 34143:41 snmpd
35 root 20 0 0 0 0 S 400.0 0.0 12790:56 ksoftirqd/2
19893 root 20 0 0 0 0 S 400.0 0.0 12570:49 kworker/0:1
20059 root 20 0 0 0 0 S 400.0 0.0 4666:30 kworker/1:1
32 root rt 0 0 0 0 S 400.0 0.0 8780:22 watchdog/2
792 root 20 0 92220 2516 632 S 400.0 0.1 7821:28 sendmail
25 root rt 0 0 0 0 S 400.0 0.0 8780:21 watchdog/0
26 root rt 0 0 0 0 S 400.0 0.0 8780:22 watchdog/1
38 root rt 0 0 0 0 S 400.0 0.0 8780:22 watchdog/3
19167 root 20 0 0 0 0 S 400.0 0.0 7804:04 kworker/3:2
Every process is either 400%, or 0%.
Here's my desktop box, just writing this email:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
10 root 20 0 0 0 0 S 200.0 0.0 35134:00 rcu_preempt
12 root 20 0 0 0 0 S 200.0 0.0 14059:47 rcuop/1
12528 root 20 0 0 0 0 S 200.0 0.0 1012:56 kworker/0:1
12999 davej 20 0 115m 1700 956 R 200.0 0.1 1:09.10 top
4799 root 20 0 0 0 0 S 200.0 0.0 3510:40 kworker/1:1
1 root 20 0 50760 5092 1648 S 0.0 0.2 3:14.96 systemd
2 root 20 0 0 0 0 S 0.0 0.0 1:40.55 kthreadd
Every process 200% or 0%.
Dave
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