From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by dpdk.org (Postfix) with ESMTP id 58514354D for ; Wed, 14 Mar 2018 15:40:27 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Mar 2018 07:40:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,470,1515484800"; d="scan'208";a="25203746" Received: from aburakov-mobl.ger.corp.intel.com (HELO [10.237.220.112]) ([10.237.220.112]) by orsmga008.jf.intel.com with ESMTP; 14 Mar 2018 07:40:25 -0700 To: Andrew Rybchenko , dev@dpdk.org Cc: Olivier MATZ References: <1516713372-10572-1-git-send-email-arybchenko@solarflare.com> <1520696382-16400-1-git-send-email-arybchenko@solarflare.com> <1520696382-16400-4-git-send-email-arybchenko@solarflare.com> From: "Burakov, Anatoly" Message-ID: Date: Wed, 14 Mar 2018 14:40:24 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1520696382-16400-4-git-send-email-arybchenko@solarflare.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v1 3/9] mempool: remove callback to get capabilities 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: , X-List-Received-Date: Wed, 14 Mar 2018 14:40:28 -0000 On 10-Mar-18 3:39 PM, Andrew Rybchenko wrote: > The callback was introduced to let generic code to know octeontx > mempool driver requirements to use single physically contiguous > memory chunk to store all objects and align object address to > total object size. Now these requirements are met using a new > callbacks to calculate required memory chunk size and to populate > objects using provided memory chunk. > > These capability flags are not used anywhere else. > > Restricting capabilities to flags is not generic and likely to > be insufficient to describe mempool driver features. If required > in the future, API which returns structured information may be > added. > > Signed-off-by: Andrew Rybchenko > --- Just a general comment - it is not enough to describe minimum memchunk requirements. With memory hotplug patchset that's hopefully getting merged in 18.05, memzones will no longer be guaranteed to be IOVA-contiguous. So, if a driver requires its mempool to not only be populated from a single memzone, but a single *physically contiguous* memzone, going by only callbacks will not do, because whether or not something should be a single memzone says nothing about whether this memzone has to also be IOVA-contiguous. So i believe this needs to stay in one form or another. (also it would be nice to have a flag that a user could pass to mempool_create that would force memzone reservation be IOVA-contiguous, but that's a topic for another conversation. prime user for this would be KNI.) -- Thanks, Anatoly