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 07A59C77B71 for ; Tue, 18 Apr 2023 10:17:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230036AbjDRKRw (ORCPT ); Tue, 18 Apr 2023 06:17:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229655AbjDRKRv (ORCPT ); Tue, 18 Apr 2023 06:17:51 -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 ESMTPS id 93A363C12 for ; Tue, 18 Apr 2023 03:17:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681813022; 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=ApoV6tQ/8bWNgsumqAtwyvPE2nYx/deLF6XAnhG6Ezo=; b=KnEh9QNOaFkB0T29JkpbGDUKFLYwA8s7JwMuR2o4cx8V3TOHEx3hvOQjX1cwsUdLX1GFav QG0T7Xl/wSvT9vFZ+lJtiI5PGvVK6oSEV5HLAIW9Bvrtwnw/rnEZl1Vd0EAblgwDS/U+mf eU3gSltnqBXmYIgCWeUb6S4jVNiRVhA= 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=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-623-zuI5xRlVOhadMQHmXqGEPw-1; Tue, 18 Apr 2023 06:17:01 -0400 X-MC-Unique: zuI5xRlVOhadMQHmXqGEPw-1 Received: by mail-ej1-f72.google.com with SMTP id kr13-20020a1709079a0d00b0093be92e6ff4so10186811ejc.23 for ; Tue, 18 Apr 2023 03:17:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681813020; x=1684405020; h=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=ApoV6tQ/8bWNgsumqAtwyvPE2nYx/deLF6XAnhG6Ezo=; b=EVgO2NVWHP2MQpA33hdQsADCu5wQYAh6WxIB6T38p28lLlZ7+xZKKnMpcTFnzUCT9v AwOMVYdwJdqS0tIrfcdHuPc7Nmy3NBW8HKDD6Q0qeQ6o0V2xECm+TF+jwry5i2qrg7/e 4j4c0ddtxZIHoiwzw9PN4lWpeezXeikNQ6zDNs7VFAGXZvb99HzbG5EATnRlEB0MjM4+ j+zSWheRFWMKPWAOcj3y/8yDgyu2siJ1g6/8GLTFoBzuodSZ/HxOuXe9PZ11Lu+Ez4OJ gIZuKsV7Nhbg59wjot7A/SnXRSqylBG3I01mfBtWUuQP3Bq9KqguXGZkc5a3zC9irRjs +o6Q== X-Gm-Message-State: AAQBX9eM9iqNubjbeO2WQ30MV22nwBclXAesIcGEp4uT9Td0KO8jwSKy jJpeqBBUS67SWtmzYhpFx058UftLAhfpsGxF/x5QaQnPfTAwEp5iQ9zo/wcb1XjDVfHRiesoU/E YfdOyKhH8Pfb6 X-Received: by 2002:a17:907:838d:b0:947:4828:4399 with SMTP id mv13-20020a170907838d00b0094748284399mr7869348ejc.12.1681813020428; Tue, 18 Apr 2023 03:17:00 -0700 (PDT) X-Google-Smtp-Source: AKy350a+9FUztTLaTcXx8PE3l5G/TqPZEC561sVQryR4LTqFxkdQ1s67cLIsu1//A4fVbtZjLVD1Og== X-Received: by 2002:a17:907:838d:b0:947:4828:4399 with SMTP id mv13-20020a170907838d00b0094748284399mr7869332ejc.12.1681813020026; Tue, 18 Apr 2023 03:17:00 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id z17-20020a170906715100b0093f822321fesm7835354ejj.137.2023.04.18.03.16.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Apr 2023 03:16:59 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 99F12AA85EB; Tue, 18 Apr 2023 12:16:58 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Kal Cutter Conley Cc: Maciej Fijalkowski , =?utf-8?B?QmrDtnJu?= =?utf-8?B?IFTDtnBlbA==?= , Magnus Karlsson , Jonathan Lemon , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jonathan Corbet , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH bpf-next v3 1/3] xsk: Support UMEM chunk_size > PAGE_SIZE In-Reply-To: References: <20230406130205.49996-1-kal.conley@dectris.com> <20230406130205.49996-2-kal.conley@dectris.com> <87sfdckgaa.fsf@toke.dk> <875ya12phx.fsf@toke.dk> <87ile011kz.fsf@toke.dk> X-Clacks-Overhead: GNU Terry Pratchett Date: Tue, 18 Apr 2023 12:16:58 +0200 Message-ID: <874jpdwl45.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Kal Cutter Conley writes: >> In addition, presumably when using this mode, the other XDP actions >> (XDP_PASS, XDP_REDIRECT to other targets) would stop working unless we >> add special handling for that in the kernel? We'll definitely need to >> handle that somehow... > > I am not familiar with all the details here. Do you know a reason why > these cases would stop working / why special handling would be needed? > For example, if I have a UMEM that uses hugepages and XDP_PASS is > returned, then the data is just copied into an SKB right? SKBs can > also be created directly from hugepages AFAIK. So I don't understand > what the issue would be. Can someone explain this concern? Well, I was asking :) It may well be that the SKB path just works; did you test this? Pretty sure XDP_REDIRECT to another device won't, though? -Toke