From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 3FDDEA0521; Tue, 3 Nov 2020 18:55:26 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id EE3862C16; Tue, 3 Nov 2020 18:55:23 +0100 (CET) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by dpdk.org (Postfix) with ESMTP id 639082B89 for ; Tue, 3 Nov 2020 18:55:22 +0100 (CET) Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.west.internal (Postfix) with ESMTP id 114E6ED1; Tue, 3 Nov 2020 12:55:20 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Tue, 03 Nov 2020 12:55:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=fm2; bh= 5Hito6pzlpxbUoUnqgPeYnb+aRIfs0KlFEOOCZEQmbU=; b=pM9IXJ+CLEcoNm48 D3dgpGkcXKDwaokc8mNEN2XZwO0ebgTfy0wE307Iu4ElIoj7L1h8s3JxvdnyEBKp tAkMYfOqCCqUQJbADjNy7vNOk5gsCxqDAO8DxzNAGEhBf4cHU5eCjkuWLQ2wm6iu CsFmUPr1W80Tvlm5HCl9FST7/xOwF2KO16btBqX0dHFsJDrr8VK1Svp45JQr4UJH 5OjqZ+6KqqHjRWiRc4A84fwm5/UgTw9pCAvw2u7dlxzkURhVy/nndvtsBU0EmpQH nHmYqb0DdOEKg+ccB8faSYGbo5YAiLzm486cYRb+iUHThmBuJD18NqOGIKQJ7JuB v3u1hg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=5Hito6pzlpxbUoUnqgPeYnb+aRIfs0KlFEOOCZEQm bU=; b=dSl2tL3ktxgdPtTfSA69VibyjNeUwQB/wh736ShTMHF3pb67bJy4n+JSS lOeqUFZVVRM4g/1z1bvNWTWyr7mjVtaQnfbYbZcI27v/BXNEzO4ykv9QndbWurzH 7sBrpO6b9oyrKRNcMMR5folI9aqipM1ttNuyJyaVOG+aMUePSh4SI2p1cDTV1aJk Pj/fOuoD2hU3pj84gCxSZNMuBdhBSzJIPS8T4DurqW6IySQl2IZGf4mB3rFGz+iX n7cBOYOZ3J9T1WVCqH4Wo97q5+EnRtztRaanViOnXT5phK6zKQ942NswgMn4aA2Y VzhBw9Hb24kZ0JCB23ML2CXcxykEg== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedruddtfedguddtgecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhm rghsucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenuc ggtffrrghtthgvrhhnpeffvdffjeeuteelfeeileduudeugfetjeelveefkeejfeeigeeh teffvdekfeegudenucffohhmrghinhepughpughkrdhorhhgnecukfhppeejjedrudefge drvddtfedrudekgeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhl fhhrohhmpehthhhomhgrshesmhhonhhjrghlohhnrdhnvght X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 71058328007D; Tue, 3 Nov 2020 12:55:17 -0500 (EST) From: Thomas Monjalon To: Stephen Hemminger Cc: dev@dpdk.org, ferruh.yigit@intel.com, david.marchand@redhat.com, bruce.richardson@intel.com, olivier.matz@6wind.com, andrew.rybchenko@oktetlabs.ru, jerinj@marvell.com, viacheslavo@nvidia.com Date: Tue, 03 Nov 2020 18:55:16 +0100 Message-ID: <11380042.DafKaVB94j@thomas> In-Reply-To: <20201103094236.7845f0eb@hermes.local> References: <20201029092751.3837177-1-thomas@monjalon.net> <35654921.Wzvq2zENnk@thomas> <20201103094236.7845f0eb@hermes.local> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH v5 00/16] remove mbuf timestamp 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 03/11/2020 18:42, Stephen Hemminger: > On Tue, 03 Nov 2020 17:20:20 +0100 > Thomas Monjalon wrote: > > 03/11/2020 17:08, Stephen Hemminger: > > > On Tue, 3 Nov 2020 15:09:15 +0100 > > > Thomas Monjalon wrote: > > > > > > > The mbuf field timestamp was announced to be removed for three reasons: > > > > - a dynamic field already exist, used for Tx only > > > > - this field always used 8 bytes even if unneeded > > > > - this field is in the first half (cacheline) of mbuf > > > > > > > > After this series, the dynamic field timestamp is used for both Rx and Tx > > > > with separate dynamic flags to distinguish when the value is meaningful > > > > without resetting the field during forwarding. > > > > > > There should be a place in documentation which describes all the > > > dynamic fields and their meaning. For example, which drivers/features > > > set the field and the exact meaning. > > > > A dynamic field can be registered by anyone, including the apps. > > So you will never get a full list. > > The meaning of each field should be defined in its context > > (driver, lib or app). > > > > > Is the timestamp in HW units, UTC units, or TSC ticks? > > > > The timestamp unit is driver-specific. > > It is explained in ethdev API: > > http://doc.dpdk.org/api/rte__ethdev_8h.html#a4346bf07a0d302c9ba4fe06baffd3196 > > > Are there are any conventions we should use in this area? > There could be overlapping usage between subsystems? The name of the field should be prefixed with the right context to avoid overlapping of different usages. It is documented here: http://doc.dpdk.org/api/rte__mbuf__dyn_8h.html