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.
WARNING: multiple messages have this Message-ID (diff)
From: Dave Airlie <airlied@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: 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.
next prev parent reply other threads:[~2010-08-16 3:30 UTC|newest]
Thread overview: 12+ 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 2:51 ` Markus Trippelsdorf
2010-08-16 3:30 ` Dave Airlie [this message]
2010-08-16 3:30 ` Dave Airlie
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 4:27 ` Linus Torvalds
2010-08-16 14:27 ` Andy Lutomirski
2010-08-16 15:13 ` [Intel-gfx] " Adam Jackson
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