From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id E49D847D0 for ; Thu, 21 Jul 2016 15:40:53 +0200 (CEST) Received: from alille-653-1-293-182.w90-1.abo.wanadoo.fr ([90.1.53.182] helo=[192.168.1.13]) by mail.droids-corp.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1bQEG6-0007d1-NO; Thu, 21 Jul 2016 15:43:28 +0200 To: Zoltan Kiss , dev@dpdk.org References: <1469034999-2732-1-git-send-email-zoltan.kiss@schaman.hu> Cc: Bruce Richardson From: Olivier Matz Message-ID: Date: Thu, 21 Jul 2016 15:40:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.1.0 MIME-Version: 1.0 In-Reply-To: <1469034999-2732-1-git-send-email-zoltan.kiss@schaman.hu> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v2] mempool: adjust name string size in related data types X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Jul 2016 13:40:54 -0000 Hi Zoltan, On 07/20/2016 07:16 PM, Zoltan Kiss wrote: > A recent patch brought up an issue about the size of the 'name' fields: > > 85cf0079 mem: avoid memzone/mempool/ring name truncation > > These relations should be observed: > > 1. Each ring creates a memzone with a prefixed name: > RTE_RING_NAMESIZE <= RTE_MEMZONE_NAMESIZE - strlen(RTE_RING_MZ_PREFIX) > > 2. There are some mempool handlers which create a ring with a prefixed > name: > RTE_MEMPOOL_NAMESIZE <= RTE_RING_NAMESIZE - strlen(RTE_MEMPOOL_MZ_PREFIX) > > 3. A mempool can create up to RTE_MAX_MEMZONE pre and postfixed memzones: > sprintf(postfix, "_%d", RTE_MAX_MEMZONE) > RTE_MEMPOOL_NAMESIZE <= RTE_MEMZONE_NAMESIZE - > strlen(RTE_MEMPOOL_MZ_PREFIX) - strlen(postfix) > > Setting all of them to 32 hides this restriction from the application. > This patch decreases the mempool and ring string size to accommodate for > these prefixes, but it doesn't apply the 3rd constraint. Applications > relying on these constants need to be recompiled, otherwise they'll run > into ENAMETOOLONG issues. > The size of the arrays are kept 32 for ABI compatibility, it can be > decreased next time the ABI changes. > > Signed-off-by: Zoltan Kiss Looks like to be a good compromise for the 16.07 release. One question however: why not taking in account the 3rd constraint? Because it may not completly fix the issue if the mempool is fragmented. We could define RTE_MEMPOOL_NAMESIZE to 24 = 32 - len('mp_') - len('_0123')) Thanks, Olivier