public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Dave Airlie <airlied@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Airlie <airlied@linux.ie>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	Zhao Yakui <yakui.zhao@intel.com>,
	Jesse Barnes <jbarnes@virtuousgeek.org>,
	Adam Jackson <ajax@redhat.com>,
	linux-kernel@vger.kernel.org,
	DRI mailing list <dri-devel@lists.freedesktop.org>
Subject: Re: Intel graphics CPU usage - SDVO detect bogosity?
Date: Mon, 16 Aug 2010 13:30:08 +1000	[thread overview]
Message-ID: <1281929408.3530.1.camel@clockmaker-el6> (raw)
In-Reply-To: <AANLkTi=NFpeyo7Q31yMfqKSP2c-2OS2ccqa=Q9CQ8bpk@mail.gmail.com>

On Sun, 2010-08-15 at 19:32 -0700, Linus Torvalds wrote:
> I started wondering why 'top' was showing an otherwise idle system as
> having a load average of 0.5+, and worker threads constantly using the
> CPU.
> 
> So I did a system-wide profile, and got the attached output (look at
> it in a really wide terminal).
> 
> There seems to be something _seriously_ wrong with i915 SDVO detect.
> This is on an Apple Mac Mini (hey, your favorite problem child!), and
> apparently it spends 20% of its non-idle CPU time just doing udelay's
> for the i2c SDVO connection detection.
> 
> That sounds a bit wrong, doesn't it?

At least we should replace mdelay with msleep in those functions.

Can you get a boot with drm.debug=4?

I wonder are we picking up a bad SDVO, the insane code retries 50 times
with a hard loop delay.

Dave.



  parent reply	other threads:[~2010-08-16  3:30 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-16  2:32 Intel graphics CPU usage - SDVO detect bogosity? Linus Torvalds
2010-08-16  2:51 ` Markus Trippelsdorf
2010-08-16  3:30 ` Dave Airlie [this message]
2010-08-16  4:01   ` Linus Torvalds
2010-08-16  4:29     ` Dave Airlie
2010-08-16  4:06 ` Andy Lutomirski
2010-08-16  4:27   ` Linus Torvalds
2010-08-16 14:27     ` Andy Lutomirski
2010-08-16 15:13       ` [Intel-gfx] " Adam Jackson

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=1281929408.3530.1.camel@clockmaker-el6 \
    --to=airlied@redhat.com \
    --cc=airlied@linux.ie \
    --cc=ajax@redhat.com \
    --cc=chris@chris-wilson.co.uk \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=jbarnes@virtuousgeek.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=yakui.zhao@intel.com \
    /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