From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: Re: [PATCH 2/2] event/sw: use dynamically-sized IQs Date: Sat, 9 Dec 2017 14:56:44 +0530 Message-ID: <20171209092643.GB13525@jerin> References: <1512011314-19682-1-git-send-email-gage.eads@intel.com> <1512011314-19682-2-git-send-email-gage.eads@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Eads, Gage" , "dev@dpdk.org" , "Richardson, Bruce" , "hemant.agrawal@nxp.com" , "nipun.gupta@nxp.com" , "santosh.shukla@caviumnetworks.com" , "pbhagavatula@caviumnetworks.com" To: "Van Haaren, Harry" Return-path: Received: from NAM01-SN1-obe.outbound.protection.outlook.com (mail-sn1nam01on0085.outbound.protection.outlook.com [104.47.32.85]) by dpdk.org (Postfix) with ESMTP id 66DFC7CBD for ; Sat, 9 Dec 2017 10:27:10 +0100 (CET) Content-Disposition: inline In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" -----Original Message----- > Date: Thu, 7 Dec 2017 17:15:35 +0000 > From: "Van Haaren, Harry" > To: "Eads, Gage" , "dev@dpdk.org" > CC: "jerin.jacob@caviumnetworks.com" , > "Richardson, Bruce" , "hemant.agrawal@nxp.com" > , "nipun.gupta@nxp.com" , > "santosh.shukla@caviumnetworks.com" , > "pbhagavatula@caviumnetworks.com" > Subject: RE: [PATCH 2/2] event/sw: use dynamically-sized IQs > > > From: Eads, Gage > > Sent: Thursday, November 30, 2017 3:09 AM > > To: dev@dpdk.org > > Cc: jerin.jacob@caviumnetworks.com; Van Haaren, Harry > > ; Richardson, Bruce > > ; hemant.agrawal@nxp.com; nipun.gupta@nxp.com; > > santosh.shukla@caviumnetworks.com; pbhagavatula@caviumnetworks.com > > Subject: [PATCH 2/2] event/sw: use dynamically-sized IQs > > > > This commit introduces dynamically-sized IQs, by switching the underlying > > data structure from a fixed-size ring to a linked list of queue 'chunks.' > > This has a number of benefits: > > - Certain corner cases were observed in which all of a pipeline's flows > > could be pinned to one port for extended periods, effectively turning a > > multi-core pipeline into single-core one. This was caused by an event > > producer having a larger new_event_threshold than the IQ depth, and > > injecting large numbers of packets that are ultimately backpressured in a > > worker's rx_ring, causing those packets' flows to be scheduled to that > > port. > > The dynamically sized IQ does not have this problem because each IQ can > > grow large enough to store all the system's events, such that > > backpressure will not reach the worker_ring. > > - Slight performance improvement (~1-2%) in high throughput scenarios, > > tested with eventdev_pipeline_sw_pmd. > > > > This implementation has a small increase in the queue storage memory > > footprint (~70KB). This commit also removes the iq_size xstat, which no > > longer applies to this implementation. > > > > Signed-off-by: Gage Eads > > Some review notes below - but nothing that needs changing. > > Acked-by: Harry van Haaren > Applied to dpdk-next-eventdev/master. Thanks. >