From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f53.google.com (mail-pg0-f53.google.com [74.125.83.53]) by dpdk.org (Postfix) with ESMTP id 285C35F2F for ; Wed, 25 Apr 2018 17:06:33 +0200 (CEST) Received: by mail-pg0-f53.google.com with SMTP id m21so10540184pgv.8 for ; Wed, 25 Apr 2018 08:06:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LUwK8Z59T+yfuF9WT6q93ynNSC98cAO5vbBHVaEpfVY=; b=MlXE+ALSmAS/w9OzSCLf8JOmZqUgz7gSBwC6XgoKZWNmKxK0K9/8VvKM1SmNiJNYiC Bnk5YlDImJ5ap3yPu58lMMZDVDKpo5IlpNcIr5kyHhDFL2jaF5/Hsx/UCfHIR2eEQDGX J64XSXbW5u6H0rxthEGmNFrqoM/C9CGJO2PsHxBiFRX091nyQZMu+CNGpETfApeR08/X yl02+6i28ZstdJjC8R7nzSsQrmRTPjkFSzrA2gWbwYzA7mRGTU1YncmK1M0vhAFFgd5b Ffu4SbJkUaeQ9N0nknNrAlMLW32yiI9W7kYmH1e6XIBvPJaso0Fo0AIguHNJ0EaivsVB VHtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LUwK8Z59T+yfuF9WT6q93ynNSC98cAO5vbBHVaEpfVY=; b=tnwmzwFdSdnNDMIq3uN79hz7jfWHSXFCFfwZ/8novl1m8lYLldw7Drz4HembLY0LDI 0ai67OspGzUEZyg/1Wwr6jZPTsSYQiaybYv3R83OVzzOL+NaeEpknKxgpU5nMLhvD8jg hvvSK30l3pxcIT7vbDcFxNKQcS4+fKwqDhKwKju0+2GGD8OoCokjNg0K16BbVKqO327n C7zzdBiMqsvkDINLgi+vb2yX6kjX2qBfoOJUyvAxtqSNA+ZF/4vVPgGLw6MlgmE1+ulz 4ly/jPPv6o1jMjwqCvjdq1r6Dd6JjQzB+piQSsz5bWRM55IUmEO3Jj0QaDzWioH3BIaY gtmg== X-Gm-Message-State: ALQs6tCkoeZ0FfbPSt8Z8tsGOwEFPpGc8ggwMFtvJIfjt2GHBuVZ6rkt PTEqt3ekgkwJ07ERhXgAY7s8ow== X-Google-Smtp-Source: AIpwx4+ye2c3b6PaeArb27W1BZJ/8IUWXQx1i8vbDWNC4A58HcCFhhgJW8ON3ZZka9ilhchgkW2tFw== X-Received: by 10.99.179.68 with SMTP id x4mr24038172pgt.132.1524668792343; Wed, 25 Apr 2018 08:06:32 -0700 (PDT) Received: from xeon-e3 (204-195-71-95.wavecable.com. [204.195.71.95]) by smtp.gmail.com with ESMTPSA id f5sm20871250pgq.77.2018.04.25.08.06.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 25 Apr 2018 08:06:32 -0700 (PDT) Date: Wed, 25 Apr 2018 08:06:29 -0700 From: Stephen Hemminger To: Thomas Monjalon Cc: Olivier Matz , Andrew Rybchenko , Yongseok Koh , wenzhuo.lu@intel.com, jingjing.wu@intel.com, dev@dpdk.org, konstantin.ananyev@intel.com, adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com Message-ID: <20180425080629.7b2a30da@xeon-e3> In-Reply-To: <1963503.R6hUdDjUTB@xps> References: <20180310012532.15809-1-yskoh@mellanox.com> <20180424191538.exjgzoif4odhndew@neon> <1963503.R6hUdDjUTB@xps> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v4 1/2] mbuf: support attaching external buffer to mbuf 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, 25 Apr 2018 15:06:33 -0000 On Tue, 24 Apr 2018 22:22:45 +0200 Thomas Monjalon wrote: > > > > > > I guess the problem that it changes INDIRECT semantics since EXTBUF > > > is added as well. I think strictly speaking it is an API change. > > > Is it OK to make it without announcement? > > > > In any case, there will be an ABI change, because an application > > compiled for 18.02 will not be able to handle these new kind of > > mbuf. > > > > So unfortunatly yes, I think this kind of changes should first be > > announced. > > > > Thomas, what do you think? > > What is the impact for the application developer? > Is there something to change in the application after this patch? Maybe the use of external buffers should be negotiated as a receiver flag (per queue) in the device driver. If device wants external buffers it sets that in capability flag, and only uses it application requests it. This allows old applications to work with no semantic surprises.