From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v8 1/2] mbuf: support attaching external buffer to mbuf Date: Fri, 27 Apr 2018 20:09:26 +0200 Message-ID: <15428823.W6WqeT6KmP@xps> References: <20180310012532.15809-1-yskoh@mellanox.com> <20180427172252.8153-1-yskoh@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org, wenzhuo.lu@intel.com, jingjing.wu@intel.com, olivier.matz@6wind.com, konstantin.ananyev@intel.com, arybchenko@solarflare.com, stephen@networkplumber.org, adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com To: Yongseok Koh Return-path: Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by dpdk.org (Postfix) with ESMTP id D5DC37D0A for ; Fri, 27 Apr 2018 20:09:29 +0200 (CEST) In-Reply-To: <20180427172252.8153-1-yskoh@mellanox.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 27/04/2018 19:22, Yongseok Koh: > This patch introduces a new way of attaching an external buffer to a mbuf. > > Attaching an external buffer is quite similar to mbuf indirection in > replacing buffer addresses and length of a mbuf, but a few differences: > - When an indirect mbuf is attached, refcnt of the direct mbuf would be > 2 as long as the direct mbuf itself isn't freed after the attachment. > In such cases, the buffer area of a direct mbuf must be read-only. But > external buffer has its own refcnt and it starts from 1. Unless > multiple mbufs are attached to a mbuf having an external buffer, the > external buffer is writable. > - There's no need to allocate buffer from a mempool. Any buffer can be > attached with appropriate free callback. > - Smaller metadata is required to maintain shared data such as refcnt. > > Signed-off-by: Yongseok Koh > Acked-by: Konstantin Ananyev > Acked-by: Olivier Matz > Acked-by: Andrew Rybchenko Series applied, thanks