From owner-freebsd-hackers@freebsd.org  Sat Feb  1 15:11:16 2020
Return-Path: <owner-freebsd-hackers@freebsd.org>
Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1])
 by mailman.nyi.freebsd.org (Postfix) with ESMTP id 892B81F9424
 for <freebsd-hackers@mailman.nyi.freebsd.org>;
 Sat,  1 Feb 2020 15:11:16 +0000 (UTC) (envelope-from slw@zxy.spb.ru)
Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 488yGW3V6xz4dXP
 for <freebsd-hackers@freebsd.org>; Sat,  1 Feb 2020 15:11:15 +0000 (UTC)
 (envelope-from slw@zxy.spb.ru)
Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD))
 (envelope-from <slw@zxy.spb.ru>)
 id 1ixuQS-0003fa-O1; Sat, 01 Feb 2020 18:11:12 +0300
Date: Sat, 1 Feb 2020 18:11:12 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: David Wolfskill <david@catwhisker.org>, freebsd-hackers@freebsd.org
Subject: Re: HT detetct
Message-ID: <20200201151112.GA8012@zxy.spb.ru>
References: <20200201142613.GA8028@zxy.spb.ru>
 <20200201143141.GL1270@albert.catwhisker.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200201143141.GL1270@albert.catwhisker.org>
User-Agent: Mutt/1.5.24 (2015-08-30)
X-SA-Exim-Connect-IP: <locally generated>
X-SA-Exim-Mail-From: slw@zxy.spb.ru
X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false
X-Rspamd-Queue-Id: 488yGW3V6xz4dXP
X-Spamd-Bar: /
Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none;
 spf=none (mx1.freebsd.org: domain of slw@zxy.spb.ru has no SPF policy when
 checking 195.70.199.98) smtp.mailfrom=slw@zxy.spb.ru
X-Spamd-Result: default: False [0.12 / 15.00]; ARC_NA(0.00)[];
 NEURAL_HAM_MEDIUM(-0.79)[-0.792,0]; FROM_HAS_DN(0.00)[];
 TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-0.07)[-0.073,0];
 MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[];
 DMARC_NA(0.00)[zxy.spb.ru]; AUTH_NA(1.00)[];
 TO_MATCH_ENVRCPT_SOME(0.00)[]; RCPT_COUNT_TWO(0.00)[2];
 R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[];
 MIME_TRACE(0.00)[0:+];
 ASN(0.00)[asn:5495, ipnet:195.70.192.0/19, country:RU];
 MID_RHS_MATCH_FROM(0.00)[];
 IP_SCORE(0.08)[asn: 5495(0.40), country: RU(0.01)];
 RCVD_COUNT_TWO(0.00)[2]
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 01 Feb 2020 15:11:16 -0000

On Sat, Feb 01, 2020 at 06:31:41AM -0800, David Wolfskill wrote:

> On Sat, Feb 01, 2020 at 05:26:14PM +0300, Slawa Olhovchenkov wrote:
> > No other way to detect HT CPU but from kvm get cpu_apic_ids and from
> > kvm get cpu_present[] and check .cpu_hyperthread?
> > ....
> 
> Not sure what context you have here (driver? shell script? other?).

kvm in driver or shell script?
c/c++ program.

> But the output of "sysctl kern.smp.threads_per_core" may be of interest
> or use in some of those contexts.

# sysctl kern.smp.threads_per_core
sysctl: unknown oid 'kern.smp.threads_per_core'

# sysctl kern.smp.threads_per_core
kern.smp.threads_per_core: 2

Hmm, like 12.1 and up.
OK, thanks!