From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38385C61DA4 for ; Fri, 3 Feb 2023 09:20:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232294AbjBCJUy (ORCPT ); Fri, 3 Feb 2023 04:20:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232356AbjBCJUU (ORCPT ); Fri, 3 Feb 2023 04:20:20 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42C055D12F for ; Fri, 3 Feb 2023 01:18:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675415887; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=epRfDPzeCVTwbxr7ZzaPb0BTAgrqd0oxNwKqq2k7gGE=; b=Da+AK1yepzzoZujPzFrN42VasVkb3RY50ooxTYWkG9Qft3tiX8fPF4TTEcZ8NNPh87zBug 2OO3/VH/HCmB0VYs14W/lUVXozVdRhwC/Hzq3Xk/OIO4Sm3vMyKvTkum6smkT8nwH+sz7h 3D8cymzFHySHbuNrmWxMPyoBwhyG3aM= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-479-QS9VGPyMOSmcErGJ14lUgA-1; Fri, 03 Feb 2023 04:18:06 -0500 X-MC-Unique: QS9VGPyMOSmcErGJ14lUgA-1 Received: by mail-ej1-f69.google.com with SMTP id bw6-20020a170906c1c600b0088e4f4830b1so3499482ejb.7 for ; Fri, 03 Feb 2023 01:18:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=epRfDPzeCVTwbxr7ZzaPb0BTAgrqd0oxNwKqq2k7gGE=; b=sXoixnnDFBzsjzOatB4WG9WF0Ug4IzBia2Cipi6rekYfmLYtZCy0aFCVJrJpEfi78M m3/UUNy34Qs/p7+IUl5IdpJb0SWY1+C+FtnJup/i8d2eqcuLVjR+fU5YktvQTHe9PX/L uQ9FfeoAZFUrCH/X7ogW9o7yll+8L4BcFpycyWuMkuzABhFgJ9vmdhCR2JWIP3nmXOpK +2AnvdshaqsnFBCbsh+yIwT0uZRWS/93Lf/MQwgT1eL7taHeW+H7AYHp+j1KP78tPb6s S3FeqOpqSAgdVwk9vmbOgPVTvPTe8rOihQ0k4dCmonDxH7RIoFTXII4KpVMUjPego4ub lqIA== X-Gm-Message-State: AO0yUKU9kOcvZWCVcrKR+mPEWKQ2Lh8eGiZj1hvefYIEhbu0KkiK1h9G S34p3QjoTKt9W8AyvaTJWA0oXfZNgSn4AxVX2JHYRjEpCWGZB2XyEDrDRiYUq38Je6ACMCzWtVR 2gowfh0oTNZOq X-Received: by 2002:a17:906:4787:b0:884:37fd:bf4c with SMTP id cw7-20020a170906478700b0088437fdbf4cmr10854180ejc.19.1675415884879; Fri, 03 Feb 2023 01:18:04 -0800 (PST) X-Google-Smtp-Source: AK7set/r1+CDvVLFdXnEssdesv7QuGqfhjJVfo5pd8868UK6ys7Bboue+Ipv1DMVtJdspKbRue9+hg== X-Received: by 2002:a17:906:4787:b0:884:37fd:bf4c with SMTP id cw7-20020a170906478700b0088437fdbf4cmr10854167ejc.19.1675415884639; Fri, 03 Feb 2023 01:18:04 -0800 (PST) Received: from redhat.com ([2.52.156.122]) by smtp.gmail.com with ESMTPSA id t24-20020a1709066bd800b0088452ca0666sm1077211ejs.196.2023.02.03.01.18.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Feb 2023 01:18:04 -0800 (PST) Date: Fri, 3 Feb 2023 04:17:59 -0500 From: "Michael S. Tsirkin" To: Xuan Zhuo Cc: Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Jason Wang , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Sebastian Andrzej Siewior , Menglong Dong , Kuniyuki Iwashima , Petr Machata , virtualization@lists.linux-foundation.org, bpf@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 00/33] virtio-net: support AF_XDP zero copy Message-ID: <20230203034212-mutt-send-email-mst@kernel.org> References: <20230202110058.130695-1-xuanzhuo@linux.alibaba.com> <5fda6140fa51b4d2944f77b9e24446e4625641e2.camel@redhat.com> <1675395211.6279888-2-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1675395211.6279888-2-xuanzhuo@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Feb 03, 2023 at 11:33:31AM +0800, Xuan Zhuo wrote: > On Thu, 02 Feb 2023 15:41:44 +0100, Paolo Abeni wrote: > > On Thu, 2023-02-02 at 19:00 +0800, Xuan Zhuo wrote: > > > XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero > > > copy feature of xsk (XDP socket) needs to be supported by the driver. The > > > performance of zero copy is very good. mlx5 and intel ixgbe already support > > > this feature, This patch set allows virtio-net to support xsk's zerocopy xmit > > > feature. > > > > > > Virtio-net did not support per-queue reset, so it was impossible to support XDP > > > Socket Zerocopy. At present, we have completed the work of Virtio Spec and > > > Kernel in Per-Queue Reset. It is time for Virtio-Net to complete the support for > > > the XDP Socket Zerocopy. > > > > > > Virtio-net can not increase the queue at will, so xsk shares the queue with > > > kernel. > > > > > > On the other hand, Virtio-Net does not support generate interrupt manually, so > > > when we wakeup tx xmit, we used some tips. If the CPU run by TX NAPI last time > > > is other CPUs, use IPI to wake up NAPI on the remote CPU. If it is also the > > > local CPU, then we wake up sofrirqd. > > > > Thank you for the large effort. > > > > Since this will likely need a few iterations, on next revision please > > do split the work in multiple chunks to help the reviewer efforts - > > from Documentation/process/maintainer-netdev.rst: > > > > - don't post large series (> 15 patches), break them up > > > > In this case I guess you can split it in 1 (or even 2) pre-req series > > and another one for the actual xsk zero copy support. > > > OK. > > I can split patch into multiple parts such as > > * virtio core > * xsk > * virtio-net prepare > * virtio-net support xsk zerocopy > > However, there is a problem, the virtio core part should enter the VHOST branch > of Michael. Then, should I post follow-up patches to which branch vhost or > next-next? > > Thanks. > Here are some ideas on how to make the patchset smaller and easier to merge: - keep everything in virtio_net.c for now. We can split things out later, but this way your patchset will not conflict with every since change merged meanwhile. Also, split up needs to be done carefully with sane APIs between components, let's maybe not waste time on that now, do the split-up later. - you have patches that add APIs then other patches use them. as long as it's only virtio net just add and use in a single patch, review is actually easier this way. - we can try merging pre-requisites earlier, then patchset size will shrink. > > > > Thanks! > > > > Paolo > >