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 A63DAC433EF for ; Sat, 9 Apr 2022 13:01:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241839AbiDINDG (ORCPT ); Sat, 9 Apr 2022 09:03:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241828AbiDINCx (ORCPT ); Sat, 9 Apr 2022 09:02:53 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3A9FE3D4A2 for ; Sat, 9 Apr 2022 06:00:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649509245; 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=vJF0+cpTjbpD0ugkGwD+TLHjTXyWijUBqPscSgAtu/A=; b=ERYw3iqs0gvlfbKDLpsgXKlqaHtEoWEJv5UMPz8l20RVjJkM2avZBOhQk+57zH590x/FTJ ISCSlXq8Jm+lwL3efa02b764Tpplr/yn/Tub2BwjQFYH1a6eUy4BSWP58KaLVSv3FoyF0D cfJMIMVhqqIUfQk82h4NGMxXcAg87do= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-163-TNDyyj9ENQCFXH3ZaiPqzQ-1; Sat, 09 Apr 2022 09:00:43 -0400 X-MC-Unique: TNDyyj9ENQCFXH3ZaiPqzQ-1 Received: by mail-ej1-f72.google.com with SMTP id 13-20020a170906328d00b006982d0888a4so5816984ejw.9 for ; Sat, 09 Apr 2022 06:00:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=vJF0+cpTjbpD0ugkGwD+TLHjTXyWijUBqPscSgAtu/A=; b=3csCLhcZ8qVHSHilyW/e2kpfM9JWlLsREiEPrS8Lj2JX5kgXkpC/tc9lP+Mu6wAd30 VuFn7ewdJRRLu/+6adiTgDsJNDqY6FswAbKI+jHezJwVCSU/Yn3aaZWwXjfdk+w0X2ze B7KZw0gfOBKsTzSU0EFIio04RD5RuorvwPu7NhH731djbo18Edxr07f0CucsN81KUrUF Y3PRBTHVbJAiyI1d7NaqOHHDqasBGp+cv5Cv1FhSciuY/eIjHUrBg9AT6juTeHnJ4b5p 7vDO2ks0jprpiSAUuCtLYK6ySKBiGU3dmLYkr+xiyE6YFj02pLL4cw41roGzzkm0Fhnu ozFg== X-Gm-Message-State: AOAM532ghA4Nnx/ptnCqtDcEKbsNxjjlh/tTk6v2vFRROY70TchCi3w1 XJEzKfMi3PbVmg0siTLJmFzetlouOg1TT99MitH7zBCWA6zExSCDsZy1n33EQUlUbVkQN72goPG pcOoP4X1dSLrk1VRi66d1ANM= X-Received: by 2002:a17:906:1ece:b0:6ce:e14:6d92 with SMTP id m14-20020a1709061ece00b006ce0e146d92mr22244035ejj.408.1649509242341; Sat, 09 Apr 2022 06:00:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy8+FcQQnwXUH+6c5Jzg6ItzZiUqT2/7YULSOWiG6w+uZCBJEMrO8AkuW2k3vg2P/dNGpl0Sg== X-Received: by 2002:a17:906:1ece:b0:6ce:e14:6d92 with SMTP id m14-20020a1709061ece00b006ce0e146d92mr22244011ejj.408.1649509241959; Sat, 09 Apr 2022 06:00:41 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id b25-20020a056402139900b0041904036ab1sm11828149edv.5.2022.04.09.06.00.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 09 Apr 2022 06:00:41 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id C0B2227551B; Sat, 9 Apr 2022 15:00:40 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: "Deric, Nemanja" , "xdp-newbies@vger.kernel.org" Cc: "Bezdeka, Florian" , Magnus Karlsson Subject: Re: Questions regarding AF_XDP (ETF, TX queue selection) In-Reply-To: References: X-Clacks-Overhead: GNU Terry Pratchett Date: Sat, 09 Apr 2022 15:00:40 +0200 Message-ID: <878rse8l8n.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: xdp-newbies@vger.kernel.org "Deric, Nemanja" writes: > Dear XDP-newbies, > > I am Nemanja Deric, and I am working as a Researcher for Industrial > Networking Department of Siemens AG (Munich, Germany). Recently, > we have started looking into AF_XDP/XDP and its applicability for some > of our industrial use cases. Thus, we have a few questions about the > technology which we hope that this mailing list can help us clarify. > > If you believe that these questions are better suited for some other > mailing list or direct email contact, please let me know so that I can > contact the correct person/mailing list. > > ETF, Timestamping: > In comparison to AF_PACKET sockets AF_XDP sockets do not support > timestamping (SOL_TXTIME) yet. There seems no way to pass such > request or meta-information to the kernel / NIC. Is that correct? We > already heard about "xdp hints" but we have failed to get further > information like plans / roadmap / implementation state / ideas. > Any pointers where to look at? Your understanding is basically correct: there's currently no support for that kind of metadata in XDP at all (which extends to AF_XDP). The effort to fix that is xdp-hints, and timestamps are explicitly part of that. That's still work in progress; there's a mailing list dedicated to this that you may want to subscribe to (and feel free to send a message there indicating your interest!): https://lists.xdp-project.net/postorius/lists/xdp-hints.xdp-project.net/ The closest you can get to a "progress report" is probably looking through the archive of that list. > TX queue selection: > AF_XDP sockets are always bound to a specific RX queue. Instead, > TX queues are "automatically" chosen by the kernel - TX is more or > less handled by NAPI. Correct? Has someone already thought about > TX queue selection? Any plans / roadmap / details according > implementation state available? +Magnus who may have an idea about this. -Toke