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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36720C433E0 for ; Fri, 12 Mar 2021 07:19:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06CE164F6D for ; Fri, 12 Mar 2021 07:19:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231380AbhCLHS4 (ORCPT ); Fri, 12 Mar 2021 02:18:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231181AbhCLHSh (ORCPT ); Fri, 12 Mar 2021 02:18:37 -0500 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B15C3C061574 for ; Thu, 11 Mar 2021 23:18:36 -0800 (PST) Received: by mail-ed1-x52d.google.com with SMTP id j3so6511738edp.11 for ; Thu, 11 Mar 2021 23:18:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UhkXsUQwFJd4p3wwdmUDZNeScmbDWk4gsHyLcLAcyoM=; b=ZrzKxjcrENP077JVJEWGhRapjHUhd5tZB7+ckUx1VtKpPNPLf6Lb0ak/FQpoBTaHXy ZuQrUh/O9Fhk8tewzuwW7y40Lun0RaTH5leRVWVtYpvkMere22VF3AfOXsOoyN06Sxeo BsLydCLRKyqcEsac0RxJ2OLbrpNYu4eFYeT3AlDpeaHIAylPU7O3FVoHaKTtYqJvlV5x BmxPnob62CTxXak9AkDh44TDqeax+d5bdD4uM5KzZh4c/6WiB7nczQsr6+KgNCbB4aR3 tlJWJ83Nq3lFDB8ECfH8AIMAeSRPmEVEjKej0C1ka5T2tQSYcbFRAbkyTOdf0VDR6jqq Qvpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=UhkXsUQwFJd4p3wwdmUDZNeScmbDWk4gsHyLcLAcyoM=; b=jgjzGJj2azsgHuLIBwKEkGhCMsF6F+QeyNA+ejCYDgcRMrpuCJqliqrr3Rtqzs+SKA E8898W5xyUSEIKhtG0sW73NJYAGCtt8tPby6Sxot3pZfuRo2Fmpkr5KEPPJS1uanjxQn /d3JDzhQbI31tUfskS9uZ8KJOjzRQSnPYHjg3X0zkmHS7x8YLWKwiOXm1wQBU4m68KoI 8hkRLpC6zglQOiPnyHIW+apSFLHtImYlK6f2F+ShKdmD9bQwRq83+8snjsAegI/Jk5Vy yfrG6aIq3baEyjOAZZfFRvOWmGYCbM6unAwgUez0vgML3UEilovaiEukvFPnzSP/EbC4 VaEQ== X-Gm-Message-State: AOAM531iSpYiPCUyXqL25Hf+5otGrmbUr91t0ETyZTdJYkmKrKHwXcQN 4LlAK8ZmVDITyF1p0hdqixQMR4Jwcv/Q2IWlZlIvLg== X-Google-Smtp-Source: ABdhPJyhpJYTJh1dw23psGNFB+CW8y3E3icZVfuXFO0A5Pk9pUSq1cqWAVpO3UBir7tMPsmcG2Mf/+Vf849IG5Ueo9Q= X-Received: by 2002:aa7:d156:: with SMTP id r22mr12827445edo.18.1615533515509; Thu, 11 Mar 2021 23:18:35 -0800 (PST) MIME-Version: 1.0 References: <20210210175423.1873-1-mike.ximing.chen@intel.com> In-Reply-To: From: Dan Williams Date: Thu, 11 Mar 2021 23:18:24 -0800 Message-ID: Subject: Re: [PATCH v10 00/20] dlb: introduce DLB device driver To: Greg KH Cc: Mike Ximing Chen , Netdev , David Miller , Jakub Kicinski , Arnd Bergmann , Pierre-Louis Bossart Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Mar 10, 2021 at 1:02 AM Greg KH wrote: > > On Wed, Feb 10, 2021 at 11:54:03AM -0600, Mike Ximing Chen wrote: > > Intel DLB is an accelerator for the event-driven programming model of > > DPDK's Event Device Library[2]. The library is used in packet processing > > pipelines that arrange for multi-core scalability, dynamic load-balancing, > > and variety of packet distribution and synchronization schemes > > The more that I look at this driver, the more I think this is a "run > around" the networking stack. Why are you all adding kernel code to > support DPDK which is an out-of-kernel networking stack? We can't > support that at all. > > Why not just use the normal networking functionality instead of this > custom char-device-node-monstrosity? Hey Greg, I've come to find out that this driver does not bypass kernel networking, and the kernel functionality I thought it bypassed, IPC / Scheduling, is not even in the picture in the non-accelerated case. So given you and I are both confused by this submission that tells me that the problem space needs to be clarified and assumptions need to be enumerated. > What is missing from todays kernel networking code that requires this > run-around? Yes, first and foremost Mike, what are the kernel infrastructure gaps and pain points that led up to this proposal?