From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from rcdn-iport-3.cisco.com (rcdn-iport-3.cisco.com [173.37.86.74]) by dpdk.org (Postfix) with ESMTP id 07DB02A07 for ; Sat, 11 Jun 2016 00:28:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=2016; q=dns/txt; s=iport; t=1465597683; x=1466807283; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=JSvACuFUb1f/k3ZKXqv3XcKPeXRqbJvW0kuNzYVFIFA=; b=fNNa1Ky2acvDg54b8CLOkvF9sGWrI5kw9PWYWblCiRzlJ2cRhqv7n77O 6MtU9/RGtNYVxVaRx+AOC71kgz0PLz6buAXHvQ8V9saaoj5Svn5RPXdoj YWjKN9UfOC6GJ5H+j1mUA6/AVFBKL8a6RZ3R+tjqB3FwFjJLJPjjlRozf s=; X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0D7AQBDPltX/5tdJa1egz6BUwa5E4IPg?= =?us-ascii?q?XqGFwKBKTgUAQEBAQEBAWUnhEUBAQEEOj8MBAIBCBEEAQEBHgkHMhQJCAIEDgU?= =?us-ascii?q?IiCi+GgEBAQEBAQEBAQEBAQEBAQEBAQEBARyGJ4RNihsFmF8BjiCBcI03hkWJJ?= =?us-ascii?q?QEeNoI5gTVuiQl/AQEB?= X-IronPort-AV: E=Sophos;i="5.26,452,1459814400"; d="scan'208";a="117458308" Received: from rcdn-core-4.cisco.com ([173.37.93.155]) by rcdn-iport-3.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jun 2016 22:28:01 +0000 Received: from XCH-RCD-009.cisco.com (xch-rcd-009.cisco.com [173.37.102.19]) by rcdn-core-4.cisco.com (8.14.5/8.14.5) with ESMTP id u5AMS1qL028822 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Fri, 10 Jun 2016 22:28:01 GMT Received: from xch-rcd-007.cisco.com (173.37.102.17) by XCH-RCD-009.cisco.com (173.37.102.19) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Fri, 10 Jun 2016 17:28:01 -0500 Received: from xch-rcd-007.cisco.com ([173.37.102.17]) by XCH-RCD-007.cisco.com ([173.37.102.17]) with mapi id 15.00.1104.009; Fri, 10 Jun 2016 17:28:01 -0500 From: "John Daley (johndale)" To: Bruce Richardson CC: "dev@dpdk.org" , "bruce.richarsdon@intel.com" Thread-Topic: [dpdk-dev] [PATCH v3 07/13] enic: use Tx completion messages instead of descriptors Thread-Index: AQHRw12eYi+MXtaE8UaRKouBlmoGZZ/jP8kA Date: Fri, 10 Jun 2016 22:28:01 +0000 Message-ID: <6fdf2e090a4142a5ba4e3b78086267a5@XCH-RCD-007.cisco.com> References: <1464071579-30072-1-git-send-email-johndale@cisco.com> <1464913377-30879-1-git-send-email-johndale@cisco.com> <1464913377-30879-8-git-send-email-johndale@cisco.com> <20160610211813.GA15176@bricha3-MOBL3> In-Reply-To: <20160610211813.GA15176@bricha3-MOBL3> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.155.161.26] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v3 07/13] enic: use Tx completion messages instead of descriptors 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: Fri, 10 Jun 2016 22:28:03 -0000 > -----Original Message----- > From: Bruce Richardson [mailto:bruce.richardson@intel.com] > Sent: Friday, June 10, 2016 2:18 PM > To: John Daley (johndale) > Cc: dev@dpdk.org; bruce.richarsdon@intel.com > Subject: Re: [dpdk-dev] [PATCH v3 07/13] enic: use Tx completion messages > instead of descriptors >=20 > On Thu, Jun 02, 2016 at 05:22:51PM -0700, John Daley wrote: > > The NIC can either DMA a separate completion message for each > > completed send or periodically just DMA an index of the last completed > > send. Switch to the second method which improves cache locality and > > performance. > > > > Signed-off-by: John Daley >=20 > Can you perhaps send me an updated wording for this commit message as > the title and commit message conflict. The title says to use completion > messages not descriptors, while the body talks about moving away from a > completion message way of working. > Is the former method a descriptor writeback method, while the latter a he= ad > pointer writeback? If so, I think the title could be: >=20 > "enic: use Tx head pointer not descriptor writeback" >=20 > or something similar. >=20 > Again, if you send on the updated commit text, I'll just update it on app= ly. I'd > ideally like to get this patchset pushed to next-net first thing Monday. Ok, I agree that it is confusing. We moved from having the hardware send a completion descriptor for every pa= cket to having it send the index of the last completed packet every once in= a while. We can use the word 'index' and 'message' to describe the 2 metho= ds and drop the word 'descriptor'. Here is a suggestion: enic: use Tx completion index instead of completion messages The NIC can either DMA a separate completion message for each completed sen= d or periodically just DMA an index of the last completed send. Switch to t= he latter method which improves cache locality and performance. Thank you, John >=20 > /Bruce