From owner-freebsd-questions@freebsd.org Fri Apr 16 00:29:21 2021 Return-Path: Delivered-To: freebsd-questions@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 E35755DE4E6 for ; Fri, 16 Apr 2021 00:29:21 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from mail.nomadlogic.org (66-165-241-226.static.hvvc.us [66.165.241.226]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mail.nomadlogic.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FLxsr5rGLz531v for ; Fri, 16 Apr 2021 00:29:19 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from [192.168.1.223] (cpe-24-24-163-126.socal.res.rr.com [24.24.163.126]) by mail.nomadlogic.org (OpenSMTPD) with ESMTPSA id c7591351 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 16 Apr 2021 00:29:12 +0000 (UTC) Subject: Re: hyperthreading To: LuMiWa , FreeBSD Questions References: <20210415192527.49375f7f@dismail.de> From: Pete Wright Message-ID: Date: Thu, 15 Apr 2021 17:29:11 -0700 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <20210415192527.49375f7f@dismail.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Rspamd-Queue-Id: 4FLxsr5rGLz531v X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of pete@nomadlogic.org designates 66.165.241.226 as permitted sender) smtp.mailfrom=pete@nomadlogic.org X-Spamd-Result: default: False [0.70 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[66.165.241.226:from]; R_SPF_ALLOW(-0.20)[+mx]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[nomadlogic.org]; NEURAL_SPAM_MEDIUM(1.00)[1.000]; NEURAL_SPAM_SHORT(1.00)[1.000]; SPAMHAUS_ZRD(0.00)[66.165.241.226:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:29802, ipnet:66.165.240.0/22, country:US]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-questions]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Apr 2021 00:29:21 -0000 On 4/15/21 4:25 PM, LuMiWa via freebsd-questions wrote: > H1! > > I have FreeBSD 13.0-RELEASE on Thinkpad T495. For now I had just Intel > processors and T495 has > > Machine class: amd64 > CPU Model: AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx > No. of Cores: 8 > > I had hyperthreading disabled in boot/loader.conf: > > machdep.hyperthreading_allowed=0 > Is with AMD processors the same. I had also installed devcpu-data. > Should I do the same on the laptop, please? yes i believe the same loader knob is used for AMD cpu's.  here's one of my hosts with an Epyc CPU: CPU: AMD EPYC 7302P 16-Core Processor                (3000.06-MHz K8-class CPU) $ sysctl machdep.hyperthreading_allowed machdep.hyperthreading_allowed: 1 $ sysctl hw.ncpu hw.ncpu: 32 $ cheers, -pete -- Pete Wright pete@nomadlogic.org @nomadlogicLA