From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <thomas@monjalon.net> Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 061982B9B for <dev@dpdk.org>; Mon, 24 Apr 2017 14:35:01 +0200 (CEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id A288D20C8C; Mon, 24 Apr 2017 08:35:00 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute1.internal (MEProxy); Mon, 24 Apr 2017 08:35:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=oGMFIFaz3qMxNz/ EHqYgUuQ09LlAepjpqkMg1LupSPg=; b=BKZJkmkXERbJVAwAfipzY2hnQumZIl+ puRN02v5oIjTf0ZX08jR2JSF2fIIUmw4r6uNSq0TM2TE/CosW2Bf8+Ds6OfXU+3g f0Zh6O+3MXBpnBcg3SAHvXOrJ2b8l5YZokKrFp98KqXuxmwQLB7y2p71X2iAjlAo yeAU8IN1dJoM= 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-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= fm1; bh=oGMFIFaz3qMxNz/EHqYgUuQ09LlAepjpqkMg1LupSPg=; b=JAJ9i3kv OiApwKemUFwgOMyE+MQ9kTGU9QysY+2S75+GN05AINEBpsV2LeH6MRvUuYkVbMw0 BrsPm4wYsYgXfntw+WBus0cai8xbrBo6zABECQ0WJNe0dNDJJv6817l4qW1c3Ryy m6LUy3hr+TGUpHvn49+7QdPbjejZxvwL07tEjhZqa/btWz7JfsMR80T4/y4xUh3c KmxCdlKS8SQxZ6KBqkYxFbI4fa3rppYTm8HxbIxCO8yFzIlJsDlbSHMV7L0nN+w0 WS4wq+YE32rruq67JuGdxEozeIk4eaD0RqJMB1SaYINGbOm9iQkYtR9xiqWRzHs4 QKkF0o1V2BRvPw== X-ME-Sender: <xms:9PD9WDfe3gXnLeC8O8RwhCB4Y4gpwBfWVcEZ7aJ2WWsaCgyaikw5hQ> X-Sasl-enc: 1LPx2n3yBI4ONM6PUWi1x/tMBE+HUYYS4JIBr0CNwEqs 1493037300 Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 4381D241E1; Mon, 24 Apr 2017 08:35:00 -0400 (EDT) From: Thomas Monjalon <thomas@monjalon.net> To: Jerin Jacob <jerin.jacob@caviumnetworks.com> Cc: dev@dpdk.org, bruce.richardson@intel.com, harry.van.haaren@intel.com, hemant.agrawal@nxp.com, gage.eads@intel.com, nipun.gupta@nxp.com, santosh.shukla@caviumnetworks.com Date: Mon, 24 Apr 2017 14:34:59 +0200 Message-ID: <1937111.PEUejtoCqE@xps> In-Reply-To: <20170421122223.24194-1-jerin.jacob@caviumnetworks.com> References: <20170421122223.24194-1-jerin.jacob@caviumnetworks.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH] ethdev: add lock-less txq capability flag X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Mon, 24 Apr 2017 12:35:01 -0000 21/04/2017 14:22, Jerin Jacob: > if this flag is advertised by a PMD, Multiple threads can > invoke rte_eth_tx_burst() concurrently on the same tx queue > without SW lock. This is an HW feature found in some NICs > and useful in the following use cases if HW supports it. Which hardware supports it? [...] > --- a/lib/librte_ether/rte_ethdev.h > +++ b/lib/librte_ether/rte_ethdev.h > +#define DEV_TX_OFFLOAD_TXQ_MT_LOCKFREE 0x00004000 > +/**< Multiple threads can invoke rte_eth_tx_burst() concurrently on the > same + * tx queue without SW lock. > + */ Why TXQ in the name? DEV_TX_OFFLOAD_MT_LOCKFREE would be enough. I wonder whether "lock free" wording is confusing because the locks are probably handled in HW. I think the good wording is "offloaded multi-thread capability", maybe with a naming like DEV_TX_OFFLOAD_MT. Anyway we should reference this flag in rte_eth_tx_burst() and give more details in doc/guides/prog_guide/poll_mode_drv.rst. Should we wait a first hardware PoC to add this flag? Candidate for 17.08?