From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f44.google.com (mail-wg0-f44.google.com [74.125.82.44]) by dpdk.org (Postfix) with ESMTP id 1734958E6 for ; Mon, 13 Oct 2014 22:18:58 +0200 (CEST) Received: by mail-wg0-f44.google.com with SMTP id y10so9326195wgg.3 for ; Mon, 13 Oct 2014 13:26:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=XelkTTrBopvP/nwzUdi/2/oJ8/3jH1gLAO5pPkRuKj8=; b=Glt6+sAOrKQJ8qfGzGCUvedp/lPd28bBYEXqBHkwVvMVSbke81+bdiEtIbXQ7B/NP3 AdQ2Qj6hCe74V4r5U2Li5iPAipn73m4BvrJoUSOyhQDeTRYTb0qhGF2LrVLKxrkq7gRo YhdYIziOKglhJ1HvXoKObiwU/v0/2Jv624e9ICJ109RRBg+PiZMm2+CrNyB0dY9qQenX wctd1T/NZwFYiqxhSV/YqLsIgNh9odvWFWDgGHMX+KVC17ySgH9+n3rMFaCPtb28P9ZA dwmLLkyHWRRBLuJvH24rP/e7PWzhK9j20SYCpdFW5m0trCE98ZKiS1DsWe2onyAcSmKd WwsA== X-Gm-Message-State: ALoCoQnFJjnD+mvn8LdZQ8ZctmGYIpRmyqGMlbRyLvDHOC9oclUkk5GfmddbOJN846rX7Xhicjd0 X-Received: by 10.180.218.230 with SMTP id pj6mr1250470wic.62.1413231999394; Mon, 13 Oct 2014 13:26:39 -0700 (PDT) Received: from xps13.localnet (136-92-190-109.dsl.ovh.fr. [109.190.92.136]) by mx.google.com with ESMTPSA id bv17sm13344503wib.13.2014.10.13.13.26.38 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Oct 2014 13:26:38 -0700 (PDT) From: Thomas Monjalon To: Alan Carew Date: Mon, 13 Oct 2014 22:26:23 +0200 Message-ID: <3264386.kAdiTFhMft@xps13> Organization: 6WIND User-Agent: KMail/4.14.1 (Linux/3.16.4-1-ARCH; KDE/4.14.1; x86_64; ; ) In-Reply-To: <1413142571-23069-1-git-send-email-alan.carew@intel.com> References: <1412003903-9061-1-git-send-email-alan.carew@intel.com> <1413142571-23069-1-git-send-email-alan.carew@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH v4 00/10] VM Power Management X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Oct 2014 20:18:58 -0000 Hi Alan, 2014-10-12 20:36, Alan Carew: > The following patches add two DPDK sample applications and an alternate > implementation of librte_power for use in virtualized environments. > The idea is to provide librte_power functionality from within a VM to address > the lack of MSRs to facilitate frequency changes from within a VM. > It is ideally suited for Haswell which provides per core frequency scaling. > > The current librte_power affects frequency changes via the acpi-cpufreq > 'userspace' power governor, accessed via sysfs. Something was preventing me from looking deeper in this big codebase, but I didn't know what sounds weird. Now I realize: the real problem is that virtualization transparency is broken for power management. So the right thing to do is to fix it in KVM. I think all this patchset is a huge workaround. Did you try to fix it with Qemu/KVM? -- Thomas