From: Ingo Molnar <mingo@elte.hu>
To: Rene Herman <rene.herman@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Jeff Garzik <jeff@garzik.org>,
Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [PATCH] CDROM: replace jiffies busyloop with msleep
Date: Wed, 23 May 2007 21:28:16 +0200 [thread overview]
Message-ID: <20070523192816.GA16603@elte.hu> (raw)
In-Reply-To: <46548ADB.60207@gmail.com>
* Rene Herman <rene.herman@gmail.com> wrote:
> The trouble there is that unless you poll the bloody thing like mad
> too much of the Q subchannels passes below you and you need a huge
> number of retries to get anything out of it. I noticed when I started
> adding audio bits that the driver took full seconds to complete some
> audio requests while the old driver was snappy in that regard. When I
> replaced our sleeping loop with a busy-wait same as the original the
> snappyness returned and moreover, reading the TOC from the CD went
> from something close to a minute to approximately a second. Thought
> that minute was just because I was dealing with an old junk 1-speed
> drive...
ouch ...
then i guess the right approach is to not use jiffies but to use a
calculated number of udelay(10) calls or so.
Ingo
next prev parent reply other threads:[~2007-05-23 19:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-22 10:25 [PATCH] CDROM: replace jiffies busyloop with msleep Thomas Gleixner
2007-05-22 10:30 ` Jeff Garzik
2007-05-22 11:21 ` Ingo Molnar
2007-05-22 11:20 ` Jens Axboe
2007-05-23 18:41 ` Rene Herman
2007-05-23 19:28 ` Ingo Molnar [this message]
2007-05-23 19:37 ` Rene Herman
2007-05-23 19:34 ` Alan Cox
2007-05-23 19:38 ` Rene Herman
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