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From: Todd Poynor <tpoynor@mvista•com>
To: brian.auld@adic•com
Cc: linuxppc-embedded@lists•linuxppc.org
Subject: Re: Kernel Preemption patch
Date: Mon, 24 Feb 2003 11:06:39 -0800	[thread overview]
Message-ID: <3E5A6D3F.9030101@mvista.com> (raw)
In-Reply-To: <5.1.0.14.2.20030224095828.03022e38@mail.ebshome.net>


At 07:56 AM 2/24/2003, brian.auld@adic•com wrote:

> However, I noticed that your 'preempt_enable' at the bottom of the
> exerp has
> been changed from 'preempt_enable' as in the RML patch, to
> 'preempt_enable_no_reshed'. What's the reason for this inconsistency?

The preempt_enable_no_reshed avoids a kernel stack overflow seen in
certain cases of heavy preemption, where each nested call to reschedule
on preemption is interrupted and again requests a preemption.  The
proper place to check for another preemption is at the top-level
interrupt/exception handler, so that we iterate and not recurse.

Oops, MontaVista needs to contribute this bug fix back to RML's public
patch, I'll put it on my list.


--
Todd


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

  reply	other threads:[~2003-02-24 19:06 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-02-24 15:56 Kernel Preemption patch brian.auld
2003-02-24 18:02 ` Eugene Surovegin
2003-02-24 19:06   ` Todd Poynor [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-02-25 14:32 brian.auld
2003-02-26  4:14 ` Matt Porter
     [not found] <995FF289C9D69747A09E42992644595405B23683@penguin.adic.com>
2003-02-24 21:15 ` Wolfgang Denk
2003-02-24 20:45 brian.auld
2003-02-24 22:29 ` Eugene Surovegin
2003-02-25  9:12   ` Stefan Roese
2003-02-25 13:24   ` Matt Porter
2003-02-26  4:18   ` Matt Porter
2003-02-26  4:25     ` Eugene Surovegin
2003-02-26  4:52       ` Matt Porter
2003-02-24 15:38 brian.auld
2003-02-24 18:05 ` Eugene Surovegin
2003-02-24 18:50 ` Matt Porter
2003-02-24 12:54 brian.auld
2003-02-23 22:28 brian.auld
2003-02-23 22:33 ` Allen Curtis
2003-02-23 22:54 ` Eugene Surovegin
2003-02-23 23:05 ` Eugene Surovegin

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