From: Jason Wessel <jason.wessel@windriver.com>
To: Dongdong Deng <libfetion@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
kgdb-bugreport@lists.sourceforge.net, "Deng,
Dongdong" <Dongdong.Deng@windriver.com>,
peterz@infradead.org
Subject: Re: [PATCH 1/3] softlockup: add sched_clock_tick() to avoid kernel warning on kgdb resume
Date: Mon, 01 Feb 2010 00:05:53 -0600 [thread overview]
Message-ID: <4B666F41.9080302@windriver.com> (raw)
In-Reply-To: <ce2c83091001312153u280c0035j9ef53fb3e8d9068d@mail.gmail.com>
Dongdong Deng wrote:
> On Fri, Jan 29, 2010 at 10:51 PM, Jason Wessel
> <jason.wessel@windriver.com> wrote:
>
>> echo 3 > /proc/sys/kernel/softlockup_thresh
>>
>> And then some kernel code in a thread like:
>> local_irq_disable();
>> printk("Disable local irq for 11 seconds\n");
>> mdelay(11000);
>> local_irq_enable();
>>
>
> Hi Jason,
>
> Maybe this problem was fixed by
> commit baf48f6577e581a9adb8fe849dc80e24b21d171d - "softlock: fix false
> panic which can occur if softlockup_thresh is reduced".
>
That is not the same problem. The fix you referenced is a corner case
where you end up with the stack trace at the point in time you reduce
the threshold. The only reason I reduce the threshold in the first
place is just to shorten the amount of time it takes to observe the problem.
You can just change the numbers for the mdelay and use the default
softlockup threshold values and still see the problem I reported.
Jason.
next prev parent reply other threads:[~2010-02-01 6:06 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-27 22:25 [PATCH 0/3] V2 kgdb regression fixes for 2.6.33 Jason Wessel
2010-01-27 22:25 ` [PATCH 1/3] softlockup: add sched_clock_tick() to avoid kernel warning on kgdb resume Jason Wessel
2010-01-29 8:07 ` Ingo Molnar
2010-01-29 14:51 ` Jason Wessel
2010-02-01 5:53 ` Dongdong Deng
2010-02-01 6:05 ` Jason Wessel [this message]
2010-02-01 6:41 ` Dongdong Deng
2010-02-01 7:27 ` [tip:core/urgent] softlockup: Add " tip-bot for Jason Wessel
2010-01-27 22:25 ` [PATCH 2/3] x86,hw_breakpoint,kgdb: kgdb to use hw_breakpoint API Jason Wessel
2010-01-27 22:25 ` [PATCH 3/3] perf,hw_breakpoint,kgdb: No mutex taken for kernel debugger Jason Wessel
2010-01-28 17:33 ` Frederic Weisbecker
2010-01-28 17:49 ` [PATCH 3/3] perf,hw_breakpoint,kgdb: No mutex taken for kerneldebugger Jason Wessel
2010-01-28 20:09 ` Frederic Weisbecker
2010-01-28 20:38 ` [PATCH 3/3] perf,hw_breakpoint,kgdb: No mutex taken forkerneldebugger Jason Wessel
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