From: Sebastian Seifert <lathander-Mmb7MZpHnFY@public.gmane.org>
To: "Yu, Luming" <luming.yu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: mutexes and preemption
Date: Wed, 3 Mar 2004 08:24:24 +0100 [thread overview]
Message-ID: <20040303072424.GA14439@ergo.gotdns.org> (raw)
In-Reply-To: <3ACA40606221794F80A5670F0AF15F8401CBB713-SRlDPOYGfgogGBtAFL8yw7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
On Wed, Mar 03, 2004 at 03:05:11PM +0800, Yu, Luming wrote:
> >
> > some vital information first: I'm using kernel 2.6.3-mm4 with
> > DSDT in ramdisk
> > patch applied, preemption is enabled, SMP disabled.
> >
>
> What about disable preemption?
>
If I disable kernel preemption,
the second release of MUT1 by the running thread happens before the acquire by
thread 3 and no error happens.
That is to say, the sequence looks as follows without preemption:
ACQUIRE ... RELEASE
ACQUIRE ... RELEASE
ACQUIRE by thread 3 ... RELEASE by thread 3
instead of
ACQUIRE ... RELEASE
ACQUIRE ... ACQUIRE by thread 3 *ERROR* ... RELEASE by thread 3 ... RELEASE
So, it seems the kernel thread that holds the mutex becomes scheduled
away because of preemption. Should it?
Sebastian
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next prev parent reply other threads:[~2004-03-03 7:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-03 7:05 mutexes and preemption Yu, Luming
[not found] ` <3ACA40606221794F80A5670F0AF15F8401CBB713-SRlDPOYGfgogGBtAFL8yw7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2004-03-03 7:24 ` Sebastian Seifert [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-03-04 1:08 Moore, Robert
[not found] ` <CFF522B18982EA4481D3A3E23B83141C01C988CE-sBd4vmA9Se6SsB6bSF6DdVDQ4js95KgL@public.gmane.org>
2004-03-04 10:22 ` Sebastian Seifert
2004-03-03 23:59 Moore, Robert
2004-03-02 22:51 Sebastian Seifert
[not found] ` <20040302225117.GA1660-nlVyBo/8EO9N0TnZuCh8vA@public.gmane.org>
2004-03-03 11:43 ` Sebastian Seifert
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