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 BD15BC25B0E for ; Tue, 16 Aug 2022 21:40:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237654AbiHPVka (ORCPT ); Tue, 16 Aug 2022 17:40:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236666AbiHPVk0 (ORCPT ); Tue, 16 Aug 2022 17:40:26 -0400 Received: from mail-qk1-f173.google.com (mail-qk1-f173.google.com [209.85.222.173]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5950674E19; Tue, 16 Aug 2022 14:40:24 -0700 (PDT) Received: by mail-qk1-f173.google.com with SMTP id n21so9162981qkk.3; Tue, 16 Aug 2022 14:40:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=OFB+vwmFlMkdVZ/s3bOlcrdQ4LPF6bvFIAzYn5YHwNY=; b=EnDfbsKJaP+d1KRnlYL77BU3Zy5ZiFNGu+gvx3abe9Jrh9lJP4Rxztj32WzA/YFbsa ScrGh++vYTDlsti6GcT1zFf7k5YEglO2Hc8EZ0kjBTJ9Ulp1oJGnz4MoSE3oWu7e+qmX 7viTkp4izlmp2pxyYcbdX0v3c5k40O5kG4eHCyB+rqvggLgMt8ta3XdnfWaZDb94fefU RE1Cxa5T+7gM69JrXsD9g6QPcVnTGjjkmHxd/Jo6/mLAHcpt9qLVnIw5D2pPmX6fE5kA NKryUQwdotsQOF/lpGbgz8X9AtDVkNQ64i4d2tIIwv3eYhR1+ItSOX0eifLwBG45R6Z9 jGSg== X-Gm-Message-State: ACgBeo0xjt5E2pa1VjzArhtnh8tFDttttRb8uMsJttuB6J11CuKMV6yW 2jwocqanCQBRRAxpwP3C5eQq4dAFKEIFGcOr X-Google-Smtp-Source: AA6agR4vvHHI+nXguuQhR5xp//MAHKz9RZ36QS2CX4onFjNpwreJWXlVrI2q6gClSAmuKS+SWLiHNg== X-Received: by 2002:a05:620a:4441:b0:6bb:6034:f1d4 with SMTP id w1-20020a05620a444100b006bb6034f1d4mr3791255qkp.451.1660686023322; Tue, 16 Aug 2022 14:40:23 -0700 (PDT) Received: from maniforge.DHCP.thefacebook.com ([2620:10d:c091:480::a5ed]) by smtp.gmail.com with ESMTPSA id br20-20020a05620a461400b006b8619a67f4sm2454118qkb.34.2022.08.16.14.40.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Aug 2022 14:40:23 -0700 (PDT) Date: Tue, 16 Aug 2022 16:39:59 -0500 From: David Vernet To: Hao Luo Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, john.fastabend@gmail.com, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, sdf@google.com, jolsa@kernel.org, tj@kernel.org, joannelkoong@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] bpf: Add user-space-publisher ringbuffer map type Message-ID: References: <20220808155248.2475981-1-void@manifault.com> <20220810011510.c3chrli27e6ebftt@maniforge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.7 (2022-08-07) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Aug 16, 2022 at 10:01:38AM -0700, Hao Luo wrote: > On Tue, Aug 16, 2022 at 8:10 AM David Vernet wrote: > > > > On Mon, Aug 15, 2022 at 02:13:13PM -0700, Hao Luo wrote: > > > > > > > > Iters allow userspace to kick the kernel, but IMO they're meant to enable > > > > data extraction from the kernel, and dumping kernel data into user-space. > > > > > > Not necessarily extracting data and dumping data. It could be used to > > > do operations on a set of objects, the operation could be > > > notification. Iterating and notifying are orthogonal IMHO. > > > > > > > What I'm proposing is a more generalizable way of driving logic in the > > > > kernel from user-space. > > > > Does that make sense? Looking forward to hearing your thoughts. > > > > > > Yes, sort of. I see the difference between iter and the proposed > > > interface. But I am not clear about the motivation of a new APis for > > > kicking callbacks from userspace. I guess maybe it will become clear, > > > when you publish a concerte RFC of that interface and integrates with > > > your userspace publisher. > > > > Fair enough -- let me remove this from the cover letter in future > > versions of the patch-set. To your point, there's probably little to be > > gained in debating the merits of adding such APIs until there's a > > concrete use-case. > > > > Yep, sounds good. I don't mean to debate :) I would like to help. If > we could build on top of existing infra and make improvements, IMHO it > would be easier to maintain. Anyway, I'm looking forward to your > proposed APIs. Don't worry, I did not take it that you were debating. I very much appreciate your thoughts and help. If and when I send out that RFC patchset, I'll be sure to cc you (if not reach out beforehand as well to discuss).