From: Arjan van de Ven <arjan@infradead.org>
To: Joerg Sommrey <jo@sommrey.de>
Cc: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] amd76x_pm: C2 powersaving for AMD K7
Date: Sun, 08 Jan 2006 20:10:10 +0100 [thread overview]
Message-ID: <1136747410.2955.29.camel@laptopd505.fenrus.org> (raw)
In-Reply-To: <20060108190337.GA22780@sommrey.de>
On Sun, 2006-01-08 at 20:03 +0100, Joerg Sommrey wrote:
> + * Locking is done using atomic_t variables, no spin locks needed.
but... there seems to be a race now:
+ smp_mb();
+ if (unlikely(atomic_read(&amd76x_stat.num_idle)
+ == num_online)) {
+ /* Invoke C2 */
+ prs->C2_cnt++;
+ inb(amd76x_pm_cfg.C2_reg);
+ break;
+ }
also.. atomic_t + manual interrupt disabling isn't by definition better
than a spinlock... when people say "spinlocks are expensive" they imply
that atomics are also expensive...
next prev parent reply other threads:[~2006-01-08 19:10 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-08 19:03 [PATCH 1/2] amd76x_pm: C2 powersaving for AMD K7 Joerg Sommrey
2006-01-08 19:05 ` [PATCH 2/2] " Joerg Sommrey
2006-01-08 19:10 ` Arjan van de Ven [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-01-10 19:46 [PATCH 1/2] " Joerg Sommrey
2006-01-11 11:20 ` Andrew Morton
2006-01-11 17:52 ` Joerg Sommrey
2005-11-04 20:12 Joerg Sommrey
2005-09-01 20:14 Joerg Sommrey
2005-09-05 14:52 ` Pavel Machek
2005-09-05 15:43 ` Tony Lindgren
2005-09-05 20:28 ` Pavel Machek
2005-09-07 7:00 ` Tony Lindgren
2005-09-07 15:18 ` Joerg Sommrey
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