From owner-freebsd-bugs@freebsd.org Tue Jan 21 21:10:58 2020 Return-Path: Delivered-To: freebsd-bugs@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 BF9C722332F for ; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 482Lmf4gQLz43cc for ; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id A037D22332E; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) Delivered-To: bugs@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 9FFB122332D for ; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 482Lmf3p8zz43cZ for ; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7DFCE1AB79 for ; Tue, 21 Jan 2020 21:10:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 00LLAwLp058172 for ; Tue, 21 Jan 2020 21:10:58 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 00LLAwjU058154 for bugs@FreeBSD.org; Tue, 21 Jan 2020 21:10:58 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 234733] Setting CPU frequency with sysctl dev.cpu.0.fr slows a Ryzen 2700X down Date: Tue, 21 Jan 2020 21:10:58 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 12.0-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: cem@freebsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jan 2020 21:10:58 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D234733 --- Comment #3 from Conrad Meyer --- I tried the following test: $ cpuset -l 0 time sha1 <~200MBfile> (burn one result for caching, then repeat 3 trials) I got average 0.24 real, 0.22 user. You might pick a slightly larger file = for bigger and more obvious differences at different steppings. Then I set CPBDis: cpucontrol -m '0xc0010015|=3D0x02000000' /dev/cpuctl0 and repeated the tests; I got average 0.29 real, 0.26 user. I ran "cpucontrol -m '0xc0010015&=3D~0x02000000' /dev/cpuctl0" and got 0.24= /0.22 again. I also tried sysctl dev.cpu.0.freq=3D3400 (on my system, dev.cpu.0.freq_lev= els: 3400/3825 2800/2765 2200/1952). cpucontrol -m '0xc0010015' did not show CPBDis. Also, SHA1 timings remained ~0.24/0.22. I tried dev.cpu.0.freq=3D2800, waited a few seconds, and restored dev.cpu.0.freq=3D3400. cpucontrol -m '0xc0010015' still did not show CPBDis. SHA1 timings seemed = to show the expected boosted performance. My CPU is a Zen1 Threadripper 1950x; perhaps this behavior is different on = Zen+ (Ryzen 2xxx), or there is some difference due to BIOSes. But you might be interested in running the same tests and seeing what you find. --=20 You are receiving this mail because: You are the assignee for the bug.=