linux-kernel - Bug (minor): microcode_intel.c applies updates to hyperthreaded cores

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Message-id: <4B17393B.7000304@majjas.com>
Date:	Wed, 02 Dec 2009 23:06:19 -0500
From:	Michael Breuer <mbreuer@...jas.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Bug (minor): microcode_intel.c applies updates to hyperthreaded cores

According to spec, microcode should only be applied to actual cores. As
things are currently structured, looks like the fix would be in
microcode_core.c. I don't think changing the loop to look for cores vs.
cpu's would affect anything adversely, but honestly am not familiar
enough with this code or other cpu types to be sure.

As far as I can tell, the only adverse impact of this issue is boot
performance in the event that microcode is applied to a large number of
processors in a hyper-threaded environment. I've only got one chip, so
no real issues here. Just happened to notice.

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