From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 75D7DA04A2; Mon, 4 Nov 2019 11:16:47 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 31C2237AF; Mon, 4 Nov 2019 11:16:47 +0100 (CET) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by dpdk.org (Postfix) with ESMTP id 7D37D378B for ; Mon, 4 Nov 2019 11:16:45 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Nov 2019 02:16:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,266,1569308400"; d="scan'208";a="402931597" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.92]) ([10.237.220.92]) by fmsmga006.fm.intel.com with ESMTP; 04 Nov 2019 02:16:43 -0800 To: Thomas Monjalon , "Hunt, David" Cc: dev@dpdk.org References: <20190724131803.30066-1-david.hunt@intel.com> <1655765.anAStuQWUM@xps> <0c0b07e4-ef84-056f-bffa-06a402fa99f6@intel.com> <2092105.X2fBbGLaSI@xps> From: "Burakov, Anatoly" Message-ID: Date: Mon, 4 Nov 2019 10:16:42 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <2092105.X2fBbGLaSI@xps> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v1] examples/power: fix oob frequency oscillations X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 01-Nov-19 11:00 PM, Thomas Monjalon wrote: > 29/10/2019 15:05, Hunt, David: >> On 27/10/2019 18:35, Thomas Monjalon wrote: >>> 06/08/2019 13:18, Thomas Monjalon: >>>> 26/07/2019 12:15, Burakov, Anatoly: >>>>> So it's biased towards scaling up quickly, but it's doing that over a >>>>> period. Please correct me if i'm wrong as i'm not really familiar with >>>>> this codebase, but, assuming the window size is long enough, you could >>>>> be missing opportunities to scale down? For example, if you get a short >>>>> burst of 1's followed by a long burst of zeroes, you're not scaling down >>>>> until you go through the entire buffer and overwrite all of the values. >>>>> I guess that's the point of oscillation prevention, but maybe you could >>>>> improve the "scale-up" part by only checking a few recent values, rather >>>>> than the entire buffer? >>>> This patch is deferred to 19.11. >>> Any news for this patch? >>> >> The algorithm was intended to be biased (strongly) towards the scale-up, >> for performance reasons. If there is a single "scale-up" in the entire >> array, then we stay up until the entire array agrees that we can scale >> down. If the user wants to relax this, then simply reduce the size of >> the array, which will have the same affect. But I had tested it with an >> array size of 32, and that gave the best results for my use cases. > > I'm not sure to understand. The patch is rejected? > I believe he was responding to my question about the algorithm's bias. Now that the matter is resolved, Acked-by: Anatoly Burakov -- Thanks, Anatoly