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 0A59BC433FE for ; Fri, 18 Nov 2022 00:32:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240496AbiKRAcP (ORCPT ); Thu, 17 Nov 2022 19:32:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240660AbiKRAcN (ORCPT ); Thu, 17 Nov 2022 19:32:13 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 875614C240 for ; Thu, 17 Nov 2022 16:31:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668731477; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+itpjDcga9mH0LamyY/OkXi7TD9WUdNLP2cV3k9ii9k=; b=X/6NtoYWaMCVuqyOIkbRp5nVzGm2W4v7eY/rE/4H0aQpDz1iAlLZHtCnmEabshSsbNy+Wd A0Nyrlv5TQYL6HUCtxg/u6dLf0rDQcla07JtN2m+dxLxgnOd/CYPr49ssdTj6l0AVf7Ccc fmW2CJnYN3UuKn2IQVamPaJIOD4arOI= 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-42-dBSYzIhjMc-aVwJX-ZOD6A-1; Thu, 17 Nov 2022 19:29:19 -0500 X-MC-Unique: dBSYzIhjMc-aVwJX-ZOD6A-1 Received: by mail-ej1-f69.google.com with SMTP id ne36-20020a1709077ba400b007aeaf3dcbcaso1967664ejc.6 for ; Thu, 17 Nov 2022 16:29:18 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+itpjDcga9mH0LamyY/OkXi7TD9WUdNLP2cV3k9ii9k=; b=6gIOYBGkY3iVCSTpKHwDBPE+wgnQEtnC8yn2kzSGWyDvmijRRe10e0gFJFOUsJ3pXY m8U/D4EOJUsQLCnPI4YvQxhK/Mt5VOFdyH87bpLz6nqmTtUq9mskcH2vI/Jr6GpqmymH aot5SBZ5wTzOVEOGUx/nnqlXreJjJ83nKDCzKyxkaysKBEbIrGnAEm9Bis5Clwu/12tP prXD2XEMVb3NHjd5uPeaf3CoegVtjfM0bCdnJgP1pNUbT08B/fZmxC0S2NlnxvsyV3+c skYsPX0rMJ3NMei1ih7taORtXewwUqTtJJ3/peRr7Yz+oQJshL1U7IiOXE2Hpw91P0zb F9EA== X-Gm-Message-State: ANoB5pm8p54+5oA7YMe7sVnlI8JSxlQ2JeyXGSWbgCL9dHUUL0Mqrzn6 n8TtRs2eqGieieM4VqTHw4I8SQILz9vY0Z54z8pGSZMHvYYmPJPa40VpGzo2u9dBdXEW/MQlFNz +wqIvpkAC+No0 X-Received: by 2002:a05:6402:e0d:b0:466:4168:6ea7 with SMTP id h13-20020a0564020e0d00b0046641686ea7mr4041703edh.273.1668731357199; Thu, 17 Nov 2022 16:29:17 -0800 (PST) X-Google-Smtp-Source: AA0mqf7JF1PQRWwlPFnvVEFf83RM2J/Pz35scEZj/jJa/EJHPfBYm4P9LtURCOCKlui+6HqGeE+lxA== X-Received: by 2002:a05:6402:e0d:b0:466:4168:6ea7 with SMTP id h13-20020a0564020e0d00b0046641686ea7mr4041673edh.273.1668731356233; Thu, 17 Nov 2022 16:29:16 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id en17-20020a056402529100b00467960d7b62sm1131575edb.35.2022.11.17.16.29.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 16:29:15 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 0F97E7A702D; Fri, 18 Nov 2022 01:29:15 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov Cc: Stanislav Fomichev , John Fastabend , Martin KaFai Lau , bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Song Liu , Yonghong Song , KP Singh , Hao Luo , Jiri Olsa , David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, Network Development Subject: Re: [xdp-hints] Re: [PATCH bpf-next 05/11] veth: Support rx timestamp metadata for xdp In-Reply-To: References: <20221115030210.3159213-1-sdf@google.com> <20221115030210.3159213-6-sdf@google.com> <87h6z0i449.fsf@toke.dk> <8735ajet05.fsf@toke.dk> <6374854883b22_5d64b208e3@john.notmuch> <34f89a95-a79e-751c-fdd2-93889420bf96@linux.dev> <878rkbjjnp.fsf@toke.dk> <6375340a6c284_66f16208aa@john.notmuch> <637576962dada_8cd03208b0@john.notmuch> <87wn7t4y0g.fsf@toke.dk> <874juxywih.fsf@toke.dk> X-Clacks-Overhead: GNU Terry Pratchett Date: Fri, 18 Nov 2022 01:29:15 +0100 Message-ID: <87sfihxfz8.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Alexei Starovoitov writes: > On Thu, Nov 17, 2022 at 3:46 PM Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> >> > >> > Ack. I can replace the unrolling with something that just resolves >> > "generic" kfuncs to the per-driver implementation maybe? That would at >> > least avoid netdev->ndo_kfunc_xxx indirect calls at runtime.. >> >> As stated above, I think we should keep the unrolling. If we end up with >> an actual CALL instruction for every piece of metadata that's going to >> suck performance-wise; unrolling is how we keep this fast enough! :) > > Let's start with pure kfuncs without requiring drivers > to provide corresponding bpf asm. > If pure kfuncs will indeed turn out to be perf limiting > then we'll decide on how to optimize them. I'm ~90% sure we'll need that optimisation, but OK, we can start from a baseline of having them be function calls... -Toke