From: John Sigler <linux.kernel@free.fr>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Pin-pointing the root of unusual application latencies
Date: Wed, 25 Jul 2007 15:20:05 +0200 [thread overview]
Message-ID: <46A74E05.50504@free.fr> (raw)
In-Reply-To: <20070725130536.GA12334@elte.hu>
(Dropping oprofile-list@lists.sourceforge.net)
Ingo Molnar wrote:
> John Sigler wrote:
>
>>> With a pair of the following in the middle:
>>>
>>> softirq--4 0.... 670us : call_rcu (rt_run_flush)
>>> softirq--4 0D..1 670us : __rcu_advance_callbacks (call_rcu)
>
>> Any idea what went wrong in the above function trace? Why is the
>> kernel spinning in circles that way?
>
> does your test-app have higher priority than softirq--4 ?
PID 4 is [softirq-timer/0] and has priority 50 in SCHED_FIFO.
My process has priority 80 in SCHED_RR. It is waiting for IRQ10.
My user-space app has higher priority than everything except
PID 2 which is [posix_cpu_timer]
Is this a priority inversion issue?
Regards.
next prev parent reply other threads:[~2007-07-25 13:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <469600F7.3060603@free.fr>
2007-07-23 9:53 ` Pin-pointing the root of unusual application latencies Ingo Molnar
2007-07-23 14:14 ` John Sigler
2007-07-23 16:04 ` Ingo Molnar
2007-07-23 16:44 ` John Sigler
2007-07-24 8:31 ` John Sigler
2007-07-24 9:20 ` John Sigler
2007-07-25 13:04 ` John Sigler
2007-07-25 13:05 ` Ingo Molnar
2007-07-25 13:20 ` John Sigler [this message]
2007-07-25 13:38 ` Ingo Molnar
2007-07-25 14:05 ` John Sigler
2007-07-25 15:28 ` Karsten Wiese
2007-07-25 15:46 ` John Sigler
2007-07-25 16:31 ` Karsten Wiese
2007-07-25 17:09 ` Len Brown
2007-07-26 8:35 ` John Sigler
2007-07-26 10:45 ` John Sigler
2007-07-26 12:02 ` John Sigler
2007-07-26 15:16 ` John Sigler
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