From owner-freebsd-acpi@FreeBSD.ORG Tue Nov 5 02:09:47 2013 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 5150FEC3; Tue, 5 Nov 2013 02:09:47 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 9BF30238A; Tue, 5 Nov 2013 02:09:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id rA529hPX029199; Tue, 5 Nov 2013 13:09:43 +1100 (EST) (envelope-from smithi@nimnet.asn.au) Date: Tue, 5 Nov 2013 13:09:43 +1100 (EST) From: Ian Smith To: Adrian Chadd Subject: Re: Xeon E5 cpu work in low status In-Reply-To: Message-ID: <20131105124254.U89530@sola.nimnet.asn.au> References: <201311041453.03864.jhb@freebsd.org> <20131104222454.GU59496@kib.kiev.ua> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Kevin Oberman , "freebsd-acpi@freebsd.org" , ?????? X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Nov 2013 02:09:47 -0000 On Mon, 4 Nov 2013, Adrian Chadd wrote: > On 4 November 2013 14:24, Konstantin Belousov wrote: > > > My Intel board DQ67OW starts with the fixed CPU speed, which is > > configurable in BIOS. Unless OS starts managing the frequency with the > > cpufreq and powerd, CPU is locked to the pre-configured speed. It was > > not easy to understand why my single-user memory b/w benchmarks show > > half of the expected throughput for the cache, until I found the setting > > and found that Intel defaults to 1/2 of the marketing frequency. > > > > For my board, it is Performance->Processor Overrides->Maximum Non-Turbo > > Ratio. It was set to 17, normal CPU mode is 34, turbo is 38 max. > > Does powerd throttle each individual core like this? I don't have > anything laptop-y that's recent enough for that to matter. Unless something's changed recently I've missed, no. My 9 box is still broken, so ref to 8.2 sources .. start with /sys/kern/kern_cpu.c, cpufreq(4) and results of find /sys/ -name "*freq*". Nate Lawson commented way back: /* * Only initialize one set of sysctls for all CPUs. In the future, * if multiple CPUs can have different settings, we can move these * sysctls to be under every CPU instead of just the first one. */ I recall that some CPUs had potential for individual settings (voltage, freq) but some only per-package rather than per-core, and then there's the thermal control settings as well. I believe Kevin's right, p4tcc and acpi_throttle should be disabled by default, on most CPUs anyway, and that at least is just a simple change to hints, as a start. It's quite a deep rabbit warren, and most docs are only in the code - eg still? no mans for most if not all of the absolute and relative cpufreq drivers mentioned in cpufreq(4), as I recall - and of course the moving targets with newer CPUs .. so have fun down there! cheers, Ian