From owner-freebsd-hackers@freebsd.org Thu Apr 29 18:33:04 2021 Return-Path: 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 A2D24632BEE for ; Thu, 29 Apr 2021 18:33:04 +0000 (UTC) (envelope-from jsm@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (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 (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FWPJJ4JgNz4vrc for ; Thu, 29 Apr 2021 18:33:04 +0000 (UTC) (envelope-from jsm@FreeBSD.org) Received: from freebsd2.freebsd.lan (mail.northatlanticmusicsupplies.com [212.237.182.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jsm) by smtp.freebsd.org (Postfix) with ESMTPSA id 4DBBFCD09 for ; Thu, 29 Apr 2021 18:33:04 +0000 (UTC) (envelope-from jsm@FreeBSD.org) Subject: Re: hwpstate_intel cpufreq and est. From: Jesper Schmitz Mouridsen To: freebsd-hackers@freebsd.org References: <226bfdd6-2d24-2dc7-79e3-7dc33a56f2a2@FreeBSD.org> Message-ID: Date: Thu, 29 Apr 2021 20:33:03 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <226bfdd6-2d24-2dc7-79e3-7dc33a56f2a2@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Technical discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Apr 2021 18:33:04 -0000 On 29.04.2021 20.09, Jesper Schmitz Mouridsen wrote: > Hi list. > > I am working on sysutils/libsysstat [1], I have maintained it over the > years. > > I even have a little testprogram [2] > > Recently I  got a new CPU which uses freq_driver: hwpstate_intel. > > It seems to me from values from dev.cpu.X.freq that this drivers > supports different freq levels per core? > > And that the BUG section in man cpufreq stating that > > "When multiple CPUs offer frequency control, they cannot be set to > different levels and must all offer the same frequency settings." > > Does not apply to hwpstate_intel? Is this correct. My current code > relies on > > this same freq on all cores bug. > > [1] https://www.freshports.org/sysutils/libsysstat > > [2] https://people.freebsd.org/~jsm/libsysstat-test.tar.gz > > Thanks > > Jesper Schmtiz Mouridsen. > I think I found the answer in https://reviews.freebsd.org/D30004: Users running newer Intel(R) CPUs may find some differences in dynamic frequency control when upgrading to FreeBSD 13.0. A new driver for the Intel(R) Speed Shift(TM) feature set, available on certain SKUs, exposes the ability for the hardware to dynamically vary the core frequencies, including on a per core basis. > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to > "freebsd-hackers-unsubscribe@freebsd.org"