* [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
@ 2011-08-23 11:20 Heiko Carstens
2011-08-23 19:12 ` Joe Perches
2011-08-23 22:36 ` David Miller
0 siblings, 2 replies; 5+ messages in thread
From: Heiko Carstens @ 2011-08-23 11:20 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar; +Cc: linux-kernel
From: Heiko Carstens <heiko.carstens@de.ibm.com>
When performing cpu hotplug tests the kernel printk log buffer gets flooded
with pointless "Switched to NOHz mode..." messages. Especially when afterwards
analyzing a dump this might have removed more interesting stuff out of the
buffer.
Assuming that switching to NOHz mode simply works just remove the printk.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
kernel/time/tick-sched.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d5097c4..8b3b014 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -640,8 +640,6 @@ static void tick_nohz_switch_to_nohz(void)
next = ktime_add(next, tick_period);
}
local_irq_enable();
-
- printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
}
/*
@@ -793,10 +791,8 @@ void tick_setup_sched_timer(void)
}
#ifdef CONFIG_NO_HZ
- if (tick_nohz_enabled) {
+ if (tick_nohz_enabled)
ts->nohz_mode = NOHZ_MODE_HIGHRES;
- printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
- }
#endif
}
#endif /* HIGH_RES_TIMERS */
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
2011-08-23 11:20 [PATCH] nohz: remove "Switched to NOHz mode" debugging messages Heiko Carstens
@ 2011-08-23 19:12 ` Joe Perches
2011-08-23 19:15 ` Stephen Boyd
2011-08-23 22:36 ` David Miller
1 sibling, 1 reply; 5+ messages in thread
From: Joe Perches @ 2011-08-23 19:12 UTC (permalink / raw)
To: Heiko Carstens; +Cc: Thomas Gleixner, Ingo Molnar, linux-kernel, Stephen Boyd
On Tue, 2011-08-23 at 13:20 +0200, Heiko Carstens wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> When performing cpu hotplug tests the kernel printk log buffer gets flooded
> with pointless "Switched to NOHz mode..." messages. Especially when afterwards
> analyzing a dump this might have removed more interesting stuff out of the
> buffer.
> Assuming that switching to NOHz mode simply works just remove the printk.
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
[]
> -
> - printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
Though I don't know if these are actually particularly
useful messages, perhaps pr_info_ratelimited() might
be appropriate instead.
> @@ -793,10 +791,8 @@ void tick_setup_sched_timer(void)
> - printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
and here.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
2011-08-23 19:12 ` Joe Perches
@ 2011-08-23 19:15 ` Stephen Boyd
2011-08-24 5:52 ` Heiko Carstens
0 siblings, 1 reply; 5+ messages in thread
From: Stephen Boyd @ 2011-08-23 19:15 UTC (permalink / raw)
To: Joe Perches; +Cc: Heiko Carstens, Thomas Gleixner, Ingo Molnar, linux-kernel
On 08/23/2011 12:12 PM, Joe Perches wrote:
> On Tue, 2011-08-23 at 13:20 +0200, Heiko Carstens wrote:
>> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>>
>> When performing cpu hotplug tests the kernel printk log buffer gets flooded
>> with pointless "Switched to NOHz mode..." messages. Especially when afterwards
>> analyzing a dump this might have removed more interesting stuff out of the
>> buffer.
>> Assuming that switching to NOHz mode simply works just remove the printk.
>> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> []
>> -
>> - printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
> Though I don't know if these are actually particularly
> useful messages, perhaps pr_info_ratelimited() might
> be appropriate instead.
Or perhaps a printk_once() would be good. Presumably the second switch
to NOHz mode wouldn't be as dangerous as the first.
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
2011-08-23 11:20 [PATCH] nohz: remove "Switched to NOHz mode" debugging messages Heiko Carstens
2011-08-23 19:12 ` Joe Perches
@ 2011-08-23 22:36 ` David Miller
1 sibling, 0 replies; 5+ messages in thread
From: David Miller @ 2011-08-23 22:36 UTC (permalink / raw)
To: heiko.carstens; +Cc: tglx, mingo, linux-kernel
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Tue, 23 Aug 2011 13:20:46 +0200
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> When performing cpu hotplug tests the kernel printk log buffer gets flooded
> with pointless "Switched to NOHz mode..." messages. Especially when afterwards
> analyzing a dump this might have removed more interesting stuff out of the
> buffer.
> Assuming that switching to NOHz mode simply works just remove the printk.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
These drive me nuts during bootup on my 128+ cpu machines :-/ Thanks
for taking care of this.
Acked-by: David S. Miller <davem@davemloft.net>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
2011-08-23 19:15 ` Stephen Boyd
@ 2011-08-24 5:52 ` Heiko Carstens
0 siblings, 0 replies; 5+ messages in thread
From: Heiko Carstens @ 2011-08-24 5:52 UTC (permalink / raw)
To: Stephen Boyd; +Cc: Joe Perches, Thomas Gleixner, Ingo Molnar, linux-kernel
On Tue, Aug 23, 2011 at 12:15:51PM -0700, Stephen Boyd wrote:
> On 08/23/2011 12:12 PM, Joe Perches wrote:
> > On Tue, 2011-08-23 at 13:20 +0200, Heiko Carstens wrote:
> >> From: Heiko Carstens <heiko.carstens@de.ibm.com>
> >>
> >> When performing cpu hotplug tests the kernel printk log buffer gets flooded
> >> with pointless "Switched to NOHz mode..." messages. Especially when afterwards
> >> analyzing a dump this might have removed more interesting stuff out of the
> >> buffer.
> >> Assuming that switching to NOHz mode simply works just remove the printk.
> >> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> > []
> >> -
> >> - printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
> > Though I don't know if these are actually particularly
> > useful messages, perhaps pr_info_ratelimited() might
> > be appropriate instead.
>
> Or perhaps a printk_once() would be good. Presumably the second switch
> to NOHz mode wouldn't be as dangerous as the first.
Let's just remove them.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-08-24 5:52 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2011-08-23 11:20 [PATCH] nohz: remove "Switched to NOHz mode" debugging messages Heiko Carstens
2011-08-23 19:12 ` Joe Perches
2011-08-23 19:15 ` Stephen Boyd
2011-08-24 5:52 ` Heiko Carstens
2011-08-23 22:36 ` David Miller
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