Subject: Re: kern/36995: ENHANCED_SPEEDSTEP dangerous on newer Core 2 Duo CPUs
To: None <kern-bug-people@netbsd.org, gnats-admin@netbsd.org,>
From: Quentin Garnier <cube@cubidou.net>
List: netbsd-bugs
Date: 09/17/2007 10:50:06
The following reply was made to PR kern/36995; it has been noted by GNATS.
From: Quentin Garnier <cube@cubidou.net>
To: Alan Barrett <apb@cequrux.com>
Cc: gnats-bugs@NetBSD.org
Subject: Re: kern/36995: ENHANCED_SPEEDSTEP dangerous on newer Core 2 Duo CPUs
Date: Mon, 17 Sep 2007 12:48:46 +0200
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On Mon, Sep 17, 2007 at 12:46:27PM +0200, Alan Barrett wrote:
> On Mon, 17 Sep 2007, jmcneill@invisible.ca wrote:
> > Proper fix: Unknown; is there a feature flag we can check when we
> > calculate est frequencies to ignore the highest value?
>=20
> Even without a feature flag, it seems that we have enough information to
> detect this situation. I'll highlight two items from your dmesg output:
Not that easily.
> > cpu0: Intel(R) Core(TM)2 Duo CPU T7100 @ 1.80GHz, 1795.65 MHz
> ^^^^^^^^^^^
E.g., my laptop's BIOS can be configured to operate at minimum speed
when powered on on battery.
--=20
Quentin Garnier - cube@cubidou.net - cube@NetBSD.org
"You could have made it, spitting out benchmarks
Owe it to yourself not to fail"
Amplifico, Spitting Out Benchmarks, Hometakes Vol. 2, 2005.
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