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 1A2BDA04C0; Thu, 17 Sep 2020 18:43:48 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 6C0D41D6C2; Thu, 17 Sep 2020 18:43:47 +0200 (CEST) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 24779E07 for ; Thu, 17 Sep 2020 18:43:45 +0200 (CEST) IronPort-SDR: U1WMcaeTgwhw0Yzl2pN0VXTZV5OAKQLKnvR23IndTT9MaBHh8gNDVD8NVF+9Zo5zww6inMo+p+ jgwaCfbG1gLw== X-IronPort-AV: E=McAfee;i="6000,8403,9747"; a="157139321" X-IronPort-AV: E=Sophos;i="5.77,271,1596524400"; d="scan'208";a="157139321" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2020 09:43:41 -0700 IronPort-SDR: rl66u+BJRgnlU7PzcTZzYJWRO+asGVbcLml3w1Cl7cA2URSzd656JBWU07xK24gOSXAg5v6/pq vd2J0M37vxoA== X-IronPort-AV: E=Sophos;i="5.77,271,1596524400"; d="scan'208";a="452381026" Received: from bricha3-mobl.ger.corp.intel.com ([10.213.24.6]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 17 Sep 2020 09:43:37 -0700 Date: Thu, 17 Sep 2020 17:43:32 +0100 From: Bruce Richardson To: "Kinsella, Ray" Cc: Honnappa Nagarahalli , Ciara Power , "dev@dpdk.org" , Neil Horman , nd Message-ID: <20200917164332.GA1580@bricha3-MOBL.ger.corp.intel.com> References: <20200807155859.63888-1-ciara.power@intel.com> <20200827161304.32300-1-ciara.power@intel.com> <20200827161304.32300-2-ciara.power@intel.com> <20200904084518.GA1627@bricha3-MOBL.ger.corp.intel.com> <188b3510-f8da-50d8-8a31-ca48d1ad8448@ashroe.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <188b3510-f8da-50d8-8a31-ca48d1ad8448@ashroe.eu> Subject: Re: [dpdk-dev] [PATCH v2 01/17] eal: add max SIMD bitwidth 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 Thu, Sep 17, 2020 at 05:31:52PM +0100, Kinsella, Ray wrote: > > > On 09/09/2020 20:30, Honnappa Nagarahalli wrote: > > > > > >>> > >> > diff --git a/lib/librte_eal/include/rte_eal.h b/lib/librte_eal/include/rte_eal.h > >>>> index ddcf6a2e7a..8148f650f2 100644 > >>>> --- a/lib/librte_eal/include/rte_eal.h > >>>> +++ b/lib/librte_eal/include/rte_eal.h > >>>> @@ -43,6 +43,13 @@ enum rte_proc_type_t { > >>>> RTE_PROC_INVALID > >>>> }; > >>>> > >>>> +enum rte_max_simd_t { > >>> We could add a RTE_MAX_SIMD = 0. Arm platforms can use this to choose > >> SVE. > >>> > >> > >> Is zero the best value for this? Would setting it to MAX_INT or some other big > >> number be better, in terms of comparisons operations, or does that just not > >> apply at all with SVE? > > I suggested zero as the bitwidth can be specified from the command line. It would be much easier to input zero vs other number. > > Right, but it doesn't end up being that intuitive as interface > 0 is enabled, 64 is not, 128 is enabled etc .... > > Suggest we use a max 16bit integer as 0xFFFF? > I can actually see 0 on command-line as being "unlimited", but for the APIs and internally, I think that it should be converted to a MAX_INT value so that the comparisons don't need to special-case zero. I agree with Honnappa, that a -1 or maxint value is awkward on commandline, but internally it's just an enum, so we can set it to whatever the most practical value is.