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 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20070523192816.GA16603@elte.hu \
--to=mingo@elte.hu \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=jeff@garzik.org \
--cc=linux-kernel@vger.kernel.org \
--cc=penberg@cs.helsinki.fi \
--cc=rene.herman@gmail.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome