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From: Andi Kleen <andi@firstfloor.org>
To: j.mell@t-online.de
Cc: Steven Rostedt <rostedt@goodmis.org>,
	linux-kernel@vger.kernel.org, suresh.b.siddha@intel.com,
	arjan@linux.intel.com
Subject: Re: CONFIG_PREEMPT causes corruption of application's FPU stack
Date: Sun, 01 Jun 2008 13:40:27 +0200	[thread overview]
Message-ID: <87wsl9fkno.fsf@basil.nowhere.org> (raw)
In-Reply-To: <200806011101.06491.j.mell@t-online.de> (j. mell's message of "Sun, 1 Jun 2008 11:01:06 +0200")

j.mell@t-online.de writes:

> or it is restored more than 
> once. Please keep in mind, that I am always running two Einstein processes 
> simultaneously on my two cores!
> I am willing to do further testing of this problem if someone can give me a 
> hint how to continue.

My bet would have been actually on aa283f49276e7d840a40fb01eee6de97eaa7e012
because it does some nasty things (enable interrupts in the middle
of __switch_to).

I looked through the old patchkit and couldn't find any specific 
PREEMPT problems. All code it changes should run with preempt_off

You could verify with sticking WARN_ON_ONCE(preemptible()) into 
all the places acc207616a91a413a50fdd8847a747c4a7324167 
changes (__unlazy_fpu, math_state_restore) and see if that triggers
anywhere.

-Andi

  reply	other threads:[~2008-06-01 11:41 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-01  9:01 CONFIG_PREEMPT causes corruption of application's FPU stack j.mell
2008-06-01 11:40 ` Andi Kleen [this message]
2008-06-01 16:47   ` Jürgen Mell
2008-06-02 21:37     ` Suresh Siddha
2008-06-02 22:57       ` Suresh Siddha
2008-06-03  6:02         ` Jürgen Mell
2008-06-04  7:44         ` Jürgen Mell
2008-06-04 10:53           ` Ingo Molnar
2008-06-04 12:55             ` Steven Rostedt
2008-06-04 13:02               ` Ingo Molnar
2008-06-01 12:12 ` Steven Rostedt
2008-06-01 17:11 ` Simon Holm Thøgersen
2008-06-02 21:31   ` Suresh Siddha
2008-06-03 13:23     ` Simon Holm Thøgersen
2008-06-03 19:43       ` Suresh Siddha
2008-06-03 21:08         ` Simon Holm Thøgersen
  -- strict thread matches above, loose matches on Subject: below --
2008-05-24 18:52 j.mell
2008-05-17 16:31 Jürgen Mell
2008-05-18 15:07 ` Steven Rostedt
2008-05-18 15:57   ` Jürgen Mell

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