From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 2E3DCA0096 for ; Wed, 10 Apr 2019 16:05:54 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id D35801B104; Wed, 10 Apr 2019 16:05:53 +0200 (CEST) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 13B497D52 for ; Wed, 10 Apr 2019 16:05:51 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Apr 2019 07:05:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,332,1549958400"; d="scan'208";a="130186556" Received: from dhunt5-mobl2.ger.corp.intel.com (HELO [10.237.210.31]) ([10.237.210.31]) by orsmga007.jf.intel.com with ESMTP; 10 Apr 2019 07:05:49 -0700 To: Phil Yang , dev@dpdk.org, thomas@monjalon.net Cc: reshma.pattan@intel.com, gavin.hu@arm.com, honnappa.nagarahalli@arm.com, nd@arm.com References: <1546508946-12552-1-git-send-email-phil.yang@arm.com> <1554692551-28275-3-git-send-email-phil.yang@arm.com> From: "Hunt, David" Message-ID: <85718290-9c5a-01f5-21ab-0f1000e4dfde@intel.com> Date: Wed, 10 Apr 2019 15:05:48 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1554692551-28275-3-git-send-email-phil.yang@arm.com> Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Transfer-Encoding: 7bit Content-Language: en-US Subject: Re: [dpdk-dev] [PATCH v4 2/3] test/distributor: replace sync builtins with atomic builtins 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" Message-ID: <20190410140548.w1ZdHvFX1lcTrrxXmD3Z6WHgpg2rMgx5xDy9JeswC4g@z> Hi Phil, On 8/4/2019 4:02 AM, Phil Yang wrote: > '__sync' built-in functions are deprecated, should use the '__atomic' > built-in instead. the sync built-in functions are full barriers, while > atomic built-in functions offer less restrictive one-way barriers, > which help performance. > > Here is the example test result on TX2: > sudo ./arm64-armv8a-linuxapp-gcc/app/test -l 112-139 \ > -n 4 --socket-mem=1024,1024 -- -i > RTE>>distributor_perf_autotest > > *** distributor_perf_autotest without this patch *** > ==== Cache line switch test === > Time for 33554432 iterations = 1519202730 ticks > Ticks per iteration = 45 > > *** distributor_perf_autotest with this patch *** > ==== Cache line switch test === > Time for 33554432 iterations = 1251715496 ticks > Ticks per iteration = 37 > > Less ticks needed for the cache line switch test. It got 17% of > performance improvement. I'm seeing about an 8% performance degradation on my platform for the cache line switch test with the patch, however the single mode and burst mode tests area showing no difference, which are the more important tests. What kind of differences are you seeing in the single/burst mode tests? Rgds, Dave. ---snip---