From: Gregory Haskins <ghaskins@novell.com>
To: Gilles Carry <Gilles.Carry@bull.net>,
Gregory Haskins <ghaskins@novell.com>,
linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org,
rostedt@goodmis.org, dvhltc@us.ibm.com, dino
Subject: Re: [PATCH 2/2] RT: remove "paranoid" limit in push_rt_task
Date: Fri, 03 Oct 2008 13:27:34 -0400 [thread overview]
Message-ID: <48E65606.6040409@novell.com> (raw)
In-Reply-To: <20081003154501.GB5032@linux.vnet.ibm.com>
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Chirag Jog wrote:
> * Gilles Carry <Gilles.Carry@bull.net> [2008-10-03 15:46:59]:
>
>
>> Sorry Greg,
>>
>> Neither PPC64 nor Intel64 make it with this patch.
>> At boot time, it stops at the BUG_ON you added:
>> 0xc00000000004eca4 is in push_rt_task (kernel/sched_rt.c:1102)
>>
> I am also confirming this issue gilles reported.
>
> Although, i have a question:
> When we enable group scheduling (CONFIG_RT_GROUP_SCHED),
> all the problems disappear.
> After skimming through the rt scheduler code, I don't feel group
> scheduling alters the behavior of push/pull strategies in any way.
>
> So I am wonder whether enabling group scheduling
> actually solves the problem or just makes it tough
> to recreate?
>
Hi Chirag,
The issue that Gilles pointed me at is a race condition. I do not
suspect GROUP_SCHED itself has anything to do with the problem other
than it changes the timing. HTH!
-Greg
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next prev parent reply other threads:[~2008-10-03 17:23 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-25 12:32 [BUG][PPC64] BUG in 2.6.26.5-rt9 causing Hang Chirag Jog
2008-09-29 18:13 ` Gregory Haskins
2008-09-29 21:18 ` Gregory Haskins
2008-09-29 21:34 ` Gregory Haskins
2008-09-29 22:00 ` Gregory Haskins
2008-09-30 4:43 ` Chirag Jog
2008-09-30 6:47 ` Gilles Carry
2008-10-01 14:22 ` [PATCH] sched: add a stacktrace on enqueue_pushable error Gregory Haskins
2008-10-02 9:42 ` Gilles Carry
2008-10-02 11:18 ` [BUG][PPC64] BUG in 2.6.26.5-rt9 causing Hang Gilles Carry
2008-10-03 12:42 ` [RT PATCH 0/2] fix for BUG_ON crash in 26.5-rt9 Gregory Haskins
2008-10-03 12:43 ` [PATCH 1/2] RT: Remove comment that is no longer true Gregory Haskins
2008-10-03 12:43 ` [PATCH 2/2] RT: remove "paranoid" limit in push_rt_task Gregory Haskins
2008-10-03 13:46 ` Gilles Carry
2008-10-03 15:45 ` Chirag Jog
2008-10-03 17:27 ` Gregory Haskins [this message]
2008-10-03 17:26 ` [RT PATCH v2 0/2] Series short description Gregory Haskins
2008-10-03 17:26 ` [RT PATCH v2 1/2] RT: Remove comment that is no longer true Gregory Haskins
2008-10-03 17:26 ` [RT PATCH v2 2/2] RT: remove "paranoid" limit in push_rt_task Gregory Haskins
2008-10-03 12:54 ` [RT PATCH 0/2] fix for BUG_ON crash in 26.5-rt9 Gregory Haskins
2008-10-06 15:14 ` [RT PATCH v3 0/2] Fix for "[BUG][PPC64] BUG in 2.6.26.5-rt9 causing Hang" Gregory Haskins
2008-10-06 15:14 ` [RT PATCH v3 1/2] RT: Remove comment that is no longer true Gregory Haskins
2008-10-06 15:14 ` [RT PATCH v3 2/2] RT: fix push_rt_task() to handle dequeue_pushable properly Gregory Haskins
2008-10-07 6:04 ` [RT PATCH v3 0/2] Fix for "[BUG][PPC64] BUG in 2.6.26.5-rt9 causing Hang" Gilles Carry
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