From: "Måns Rullgård" <mru@mru.ath.cx>
To: linux-kernel@vger.kernel.org
Subject: Re: [ANNOUNCE] Linux 2.6 Real Time Kernel
Date: Sat, 09 Oct 2004 12:51:02 +0200 [thread overview]
Message-ID: <yw1x3c0orwq1.fsf@mru.ath.cx> (raw)
In-Reply-To: <41677E4D.1030403@mvista.com>
Sven-Thorsten Dietrich <sdietrich@mvista.com> writes:
> +#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
> +/*
> + * This could be a long-held lock. If another CPU holds it for a long time,
> + * and that CPU is not asked to reschedule then *this* CPU will spin on the
> + * lock for a long time, even if *this* CPU is asked to reschedule.
> + *
> + * So what we do here, in the slow (contended) path is to spin on the lock by
> + * hand while permitting preemption.
> + *
> + * Called inside preempt_disable().
> + */
> +
> +/* these functions are only called from inside spin_lock
> + * and old_write_lock therefore under spinlock substitution
> + * they will only be passed old spinlocks or old rwlocks as parameter
> + * there are no issues with modified mutex behavior here. */
> +
> +#endif /* defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) */
May I inquire as to the purpose of placing a couple of comments under
an #ifdef?
--
Måns Rullgård
mru@mru.ath.cx
next prev parent reply other threads:[~2004-10-09 10:51 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-09 5:59 Sven-Thorsten Dietrich
2004-10-09 6:40 ` Lee Revell
2004-10-09 7:33 ` Daniel Walker
2004-10-09 7:42 ` Lee Revell
2004-10-09 23:40 ` Matthias Urlichs
2004-10-09 8:52 ` Lee Revell
2004-10-09 23:20 ` Dave Hansen
2004-10-09 23:24 ` Lee Revell
2004-10-09 10:51 ` Måns Rullgård [this message]
2004-10-09 13:15 ` Måns Rullgård
2004-10-09 21:20 ` Lee Revell
2004-10-09 21:35 ` Måns Rullgård
2004-10-09 21:37 ` Lee Revell
2004-10-09 21:45 ` Måns Rullgård
2004-10-09 21:55 ` Lee Revell
2004-10-09 22:21 ` Måns Rullgård
2004-10-09 23:52 ` Lee Revell
2004-10-10 0:05 ` Måns Rullgård
2004-10-10 0:45 ` Lee Revell
2004-10-10 1:05 ` Måns Rullgård
2004-10-10 1:09 ` Lee Revell
2004-10-10 0:43 ` Micha Feigin
2004-10-10 1:08 ` Måns Rullgård
2004-10-09 17:41 ` Karim Yaghmour
2004-10-09 18:30 ` Lee Revell
2004-10-09 21:26 ` stefan.eletzhofer
2004-10-09 19:30 ` Lee Revell
2004-10-09 19:38 ` Måns Rullgård
2004-10-09 21:38 ` stefan.eletzhofer
2004-10-09 19:47 ` Lee Revell
2004-10-09 20:11 ` Karim Yaghmour
2004-10-09 20:14 ` Lee Revell
2004-10-09 20:53 ` Karim Yaghmour
2004-10-09 20:59 ` Lee Revell
2004-10-09 20:20 ` Robert Love
2004-10-09 20:25 ` Lee Revell
2004-10-10 1:15 ` Lee Revell
2004-10-10 8:46 ` Ingo Molnar
2004-10-10 19:41 ` Daniel Walker
2004-10-10 19:46 ` Ingo Molnar
2004-10-10 21:20 ` Andrew Morton
2004-10-10 21:59 ` Ingo Molnar
2004-10-11 17:53 ` Daniel Walker
2004-10-11 20:49 ` Ingo Molnar
2004-10-11 21:44 ` Sven Dietrich
2004-10-11 21:54 ` Ingo Molnar
2004-10-11 23:05 ` Sven Dietrich
2004-10-12 5:50 ` Ingo Molnar
2004-10-14 5:09 ` Dipankar Sarma
2004-10-14 7:18 ` Ingo Molnar
2004-10-15 14:59 ` Paul E. McKenney
2004-10-15 15:45 ` Ingo Molnar
2004-10-15 16:40 ` Paul E. McKenney
2004-10-15 16:45 ` Paul E. McKenney
2004-10-17 17:12 ` Ingo Molnar
2004-10-12 18:50 ` Daniel Walker
2004-10-12 19:46 ` [Ext-rt-dev] " Thomas Gleixner
2004-10-12 20:31 ` Sven Dietrich
2004-10-12 20:37 ` Thomas Gleixner
2004-10-13 0:30 ` George Anzinger
2004-10-12 21:12 ` Bill Huey
2004-10-12 21:24 ` Bill Huey
2004-10-12 21:32 ` Thomas Gleixner
2004-10-12 23:13 ` Bill Huey
2004-10-12 21:41 ` Sven Dietrich
2004-10-12 22:57 ` Bill Huey
2004-10-12 23:17 ` Adam Heath
2004-10-12 23:36 ` Lee Revell
2004-10-12 23:25 ` Thomas Gleixner
2004-10-13 2:02 ` K.R. Foley
2004-10-13 13:39 ` Martijn Sipkema
2004-10-13 13:26 ` La Monte H.P. Yarroll
2004-10-13 15:04 ` Martijn Sipkema
2004-10-13 14:55 ` Kurt Wall
2004-10-13 14:52 ` Christoph Hellwig
2004-10-13 15:56 ` Lee Revell
2004-10-13 16:13 ` Robert Love
2004-10-13 17:14 ` Martijn Sipkema
2004-10-13 3:55 ` Bill Huey
2004-10-12 22:00 ` Thomas Gleixner
2004-10-12 22:36 ` Bill Huey
2004-10-12 23:10 ` Thomas Gleixner
2004-10-12 23:33 ` Bill Huey
2004-10-12 23:37 ` Thomas Gleixner
2004-10-12 23:52 ` Bill Huey
2004-10-13 0:59 ` Valdis.Kletnieks
2004-10-10 12:21 ` John Richard Moser
2004-10-10 17:26 ` Lee Revell
2004-10-10 18:45 ` John Richard Moser
2004-10-10 20:20 ` Ingo Molnar
2004-10-10 20:44 ` John Richard Moser
2004-10-10 17:29 ` Daniel Walker
2004-10-09 11:38 John Hedditch
2004-10-09 22:54 Sven Dietrich
2004-10-11 15:28 Vadim Lebedev
2004-10-11 15:50 ` Eugeny S. Mints
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