From owner-freebsd-bugs@FreeBSD.ORG  Sat Sep 18 08:50:07 2010
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@hub.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 89E6010656C3
	for <freebsd-bugs@hub.freebsd.org>;
	Sat, 18 Sep 2010 08:50:07 +0000 (UTC)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (freefall.freebsd.org
	[IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 5E6398FC15
	for <freebsd-bugs@hub.freebsd.org>;
	Sat, 18 Sep 2010 08:50:07 +0000 (UTC)
Received: from freefall.freebsd.org (localhost [127.0.0.1])
	by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id o8I8o7ZJ020474
	for <freebsd-bugs@freefall.freebsd.org>; Sat, 18 Sep 2010 08:50:07 GMT
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.14.4/8.14.4/Submit) id o8I8o70H020473;
	Sat, 18 Sep 2010 08:50:07 GMT (envelope-from gnats)
Date: Sat, 18 Sep 2010 08:50:07 GMT
Message-Id: <201009180850.o8I8o70H020473@freefall.freebsd.org>
To: freebsd-bugs@FreeBSD.org
From: Andriy Gapon <avg@freebsd.org>
Cc: 
Subject: Re: kern/145385: [cpu] Logical processor cannot be disabled for some
 SMT-enabled Intel procs
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
Reply-To: Andriy Gapon <avg@freebsd.org>
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 18 Sep 2010 08:50:07 -0000

The following reply was made to PR kern/145385; it has been noted by GNATS.

From: Andriy Gapon <avg@freebsd.org>
To: bug-followup@freebsd.org, gcooper@freebsd.org,
        Jeff Roberson <jroberson@jroberson.net>
Cc:  
Subject: Re: kern/145385: [cpu] Logical processor cannot be disabled for some
 SMT-enabled Intel procs
Date: Sat, 18 Sep 2010 11:48:39 +0300

 Regarding the part of the patch that sets logical_cpus - I don't really
 understand what logical_cpus represents.
 It seems that in topo_probe_0x4() it's set to maximum (possible) number of
 logical CPUs per whole package (for BSP package).  In topo_probe_0xb(), as
 you've spotted, it was not set at all.
 
 We already have cpu_logical variable (talk about confusing names) and that
 represents number of logical CPUs per core.
 
 So, I think that logical_cpus should be abolished altogether and cpu_logical
 should be used in its place.
 That would be the end of topo_probe_0x4() where hyperthreading_cpus is assigned
 with fallback value and init_secondary() where it's used to set logical_cpus_mask.
 
 P.S. The code also doesn't seem to properly handle a case where
 boot_cpu_id % logical_cpus != 0
 and/or
 boot_cpu_id % hyperthreading_cpus !=0
 Not sure if that ever happens in real systems, though.
 
 -- 
 Andriy Gapon