From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, Pavel Machek <pavel@ucw.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Nigel Cunningham <nigel@nigel.suspend2.net>,
Uli Luckas <u.luckas@road.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm] PM: Prevent frozen user mode helpers from failing the freezing of tasks (rev. 2)
Date: Wed, 04 Jul 2007 07:19:12 +1000 [thread overview]
Message-ID: <1183497552.3388.8.camel@localhost.localdomain> (raw)
In-Reply-To: <20070703174503.GB108@tv-sign.ru>
> Actually, spinlock_t is not suitable. Because spin_unlcok() does NOT imply
> mb(). The subsequent wait_event_timeout()->atomic_read() may leak into the
> critical section.
>
> We can use set_mb(), if we don't want to play with smp_mb() by hand :)
spin_unlock implies a smp_wmb() but yeah, not a full mb(), though having
a read leak into a critical section is generally not an issue.
Ben.
next prev parent reply other threads:[~2007-07-03 21:20 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-25 21:52 Rafael J. Wysocki
2007-06-25 21:50 ` Nigel Cunningham
2007-06-25 21:55 ` Pavel Machek
2007-06-25 22:27 ` Rafael J. Wysocki
2007-06-26 8:48 ` Pavel Machek
2007-07-03 5:31 ` Benjamin Herrenschmidt
2007-06-26 12:02 ` Oleg Nesterov
2007-07-03 5:30 ` Benjamin Herrenschmidt
2007-07-03 13:19 ` Rafael J. Wysocki
2007-07-03 13:36 ` Rafael J. Wysocki
2007-07-03 17:45 ` Oleg Nesterov
2007-07-03 21:19 ` Benjamin Herrenschmidt [this message]
2007-06-26 8:07 ` Uli Luckas
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