From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Richardson Subject: Re: Performance regression in DPDK 1.8/2.0 Date: Tue, 28 Apr 2015 11:58:14 +0100 Message-ID: <20150428105814.GB7484@bricha3-MOBL3> References: <6DC6DE50-F94F-419C-98DF-3AD8DCD4F69D@net.in.tum.de> <23D2CA18-1875-4182-8DEE-9F6393011D2C@net.in.tum.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "dev-VfR2kkLFssw@public.gmane.org" To: Paul Emmerich Return-path: Content-Disposition: inline In-Reply-To: <23D2CA18-1875-4182-8DEE-9F6393011D2C-mrRt1sWyIK0ZId6A0yLOdQ@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Tue, Apr 28, 2015 at 12:28:34AM +0200, Paul Emmerich wrote: > Let me know if you need any additional information. > I'd also be interested in the configuration that resulted in the 20% speed- > up that was mentioned in the original mbuf patch > > Paul > The speed-up would be for apps that were doing RX of scattered packets, i.e. across mbufs. Before 1.8, this was using a scalar function which was rather slow compared to the fast-path vector function. In 1.8 we introduced a new vector function which supported scattered packets - it still isn't as fast as the non-scattered packet RX function, but it was a good improvement over the older version. /Bruce