From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: XDP performance regression due to CONFIG_RETPOLINE Spectre V2 Date: Mon, 16 Apr 2018 23:15:50 -0700 Message-ID: <20180417061550.GA21067@infradead.org> References: <20180412155029.0324fe58@redhat.com> <20180416122706.GA20624@infradead.org> <20180416230704.65629b9f@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , "xdp-newbies@vger.kernel.org" , "netdev@vger.kernel.org" , Christoph Hellwig , David Woodhouse , William Tu , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , "Karlsson, Magnus" , Alexander Duyck , Arnaldo Carvalho de Melo To: Jesper Dangaard Brouer Return-path: Received: from bombadil.infradead.org ([198.137.202.133]:59980 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbeDQGP4 (ORCPT ); Tue, 17 Apr 2018 02:15:56 -0400 Content-Disposition: inline In-Reply-To: <20180416230704.65629b9f@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Apr 16, 2018 at 11:07:04PM +0200, Jesper Dangaard Brouer wrote: > On X86 swiotlb fallback (via get_dma_ops -> get_arch_dma_ops) to use > x86_swiotlb_dma_ops, instead of swiotlb_dma_ops. I also included that > in below fix patch. x86_swiotlb_dma_ops should not exist any mor, and x86 now uses dma_direct_ops. Looks like you are applying it to an old kernel :) > Performance improved to 8.9 Mpps from approx 6.5Mpps. > > (This was without my bulking for net_device->ndo_xdp_xmit, so that > number should improve more). What is the number for the otherwise comparable setup without repolines?