From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 2/2] drm/i915: load a ring frequency scaling table Date: Mon, 27 Jun 2011 20:40:08 +0100 Message-ID: <1309203608_30586@CP5-2952> References: <1308939194-3568-1-git-send-email-jbarnes@virtuousgeek.org> <1308939194-3568-2-git-send-email-jbarnes@virtuousgeek.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from fireflyinternet.com (server109-228-6-236.live-servers.net [109.228.6.236]) by gabe.freedesktop.org (Postfix) with ESMTP id 35C849E7C8 for ; Mon, 27 Jun 2011 12:40:12 -0700 (PDT) In-Reply-To: <1308939194-3568-2-git-send-email-jbarnes@virtuousgeek.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Jesse Barnes , intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Fri, 24 Jun 2011 11:13:14 -0700, Jesse Barnes wrote: > The ring frequency scaling table tells the PCU to treat certain GPU > frequencies as if they were a given CPU frequency for purposes of > scaling the ring frequency. Normally the PCU will scale the ring > frequency based on the CPU P-state, but with the table present, it will > also take the GPU frequency into account. So it wasn't picking up max-cpu-freq even though I have CONFIG_CPU_FREQ and the various ACPI and Intel cpu drivers. Taking a hint from x86/kvm, I used tsc_khz instead of the default 3000. nexuiz @10x7 nopatch -> 3000 -> 3300 [tsc_khz] uncached: 43.2 44.4 44.8 llc: 51.3 52.3 At max_freq=3000, a cpu busy loop was still able to nudge it up to the same speed as using the max_freq=3300 value. -Chris -- Chris Wilson, Intel Open Source Technology Centre