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From: Dave Jones <davej@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: paulmck@linux.vnet.ibm.com,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: rcu_preempt running flat out on idle desktop.
Date: Thu, 6 Jun 2013 11:31:36 -0400	[thread overview]
Message-ID: <20130606153136.GA12823@redhat.com> (raw)
In-Reply-To: <20130514012105.GB12749@somewhere>

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


  reply	other threads:[~2013-06-06 15:32 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-08 20:30 rcu_preempt running flat out on idle desktop Dave Jones
2013-05-08 20:52 ` Paul E. McKenney
2013-05-08 20:56   ` Dave Jones
2013-05-08 21:16     ` Paul E. McKenney
2013-05-08 21:17       ` Dave Jones
2013-05-08 22:20         ` Paul E. McKenney
2013-05-09  9:04     ` Frederic Weisbecker
2013-05-09  9:20       ` Ingo Molnar
2013-05-09 21:02 ` Frederic Weisbecker
2013-05-09 21:10   ` Dave Jones
2013-05-14  1:21     ` Frederic Weisbecker
2013-06-06 15:31       ` Dave Jones [this message]
2013-06-06 15:43         ` Frederic Weisbecker
2013-06-06 23:10           ` Dave Jones
2013-06-12 15:34           ` Dave Jones
2013-06-20 19:10             ` Dave Jones
2013-06-23 10:58               ` Ingo Molnar
2013-07-01 12:10                 ` Frederic Weisbecker

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