From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH v3 01/39] examples/l2fwd: convert to new ethdev offloads API Date: Mon, 15 Jan 2018 11:56:57 +0000 Message-ID: <3726aa20-c62a-7a90-c18a-e06ec3153a16@intel.com> References: <89b45470-1868-0a1a-02a3-5c34ce1ac48e@intel.com> <4e57e260-822f-a96a-1b1c-429e54b76d60@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit To: Shahaf Shuler , "dev@dpdk.org" Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 9608A397D for ; Mon, 15 Jan 2018 12:57:00 +0100 (CET) In-Reply-To: Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 1/15/2018 11:41 AM, Shahaf Shuler wrote: > Monday, January 15, 2018 1:34 PM, Ferruh Yigit: >>>> Currently no PMD seems implemented it. >>> >>> Sure, >>> >>> FAST_FREE offload is the logical AND between the old txqflags of: >>> ETH_TXQ_FLAGS_NOREFCOUNT >>> ETH_TXQ_FLAGS_NOMULTMEM >>> >>> The offload is just a performance optimization. As specified in the >> documentation [1] it enables the PMDs to further optimize the data path >> given the guarantees from the application. >>> Not having it means possible performance degradation for some PMD >> which rely on it. >>> >>> There is no PMD which implement it yet since not all PMDs moved to the >> new offloads API. However this flag is tested and translated into txqflags as >> part of rte_eth_convert_txq_offloads function. >>> Relevant PMDs for this offload will be: sfc, thunderx and i40e. >> >> Thank you for clarification, I am OK to have it. >> >> But since currently no PMD provide "DEV_TX_OFFLOAD_MBUF_FAST_FREE" >> capability, and default txq_flags is overwritten, some PMDs lost this >> optimization until they implement new capability, right? > > Yes this is correct, a good motivation to convert :). My concern is being close to the integration deadline and if this patch cause performance drop for some PMDs. But I guess we can get the related PMD fixes almost until release if an issue observed, so this gives time to PMD maintainers. For series, Reviewed-by: Ferruh Yigit > From the examples and testpmd part everything is ready. Just need for the PMD to report back the capability to have this offload. >