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 58DE4C25B0E for ; Tue, 16 Aug 2022 15:10:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229809AbiHPPKG (ORCPT ); Tue, 16 Aug 2022 11:10:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230009AbiHPPKE (ORCPT ); Tue, 16 Aug 2022 11:10:04 -0400 Received: from mail-qv1-f42.google.com (mail-qv1-f42.google.com [209.85.219.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB4E2543CF; Tue, 16 Aug 2022 08:10:02 -0700 (PDT) Received: by mail-qv1-f42.google.com with SMTP id mk9so8048858qvb.11; Tue, 16 Aug 2022 08:10:02 -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=dmgWwEwfSK7FGsGGvHTpCWRuqiYbuUsXIkCtXthtW4o=; b=h64S4wkiwJ9kr5LkPNu1MnA4VHptnYRU5RBoLqa6wrSsRQxzuQyzGWVpo2sCiG13KX ogJBJ9XN2yee8BRFyZ5CQ8LP2SEqtCk8DrtlBMOO/HwxlLjJ+a08aWTE9uE6wFTxq5Bo 7uk2LpAKGZyxL8A1k/JGCGcrQJZe/Owec0uPZhnPyKBFAiV7nNth7sG9jd6KggEpjf6F AH5w9W1gWm3Yy3KZ9wt2pDzRt4IWOxf/JSK3ElWDFU9DTZ6EekuuMvBYTgokQHXvUgyN hkMiCFuntWmNG0fJFJXgP0BdxhvmiqPM0FsBDa7A5buVP3UdQrPR038PFeioPhS+y9ca E2+A== X-Gm-Message-State: ACgBeo0QyT0R1xQ/d9vQ8zgUBHp34V6TwXXJBuU6Na2r2LJvRhVgBFem qnoee4Bt/Ooiu3YKrlI3B+sYq6TnAFfKcJxm X-Google-Smtp-Source: AA6agR4EeFp05FpPHq8UdmVOXNNu464JjT1fmdsjyoMQjlwI69GiHM8ow57TAxJ2PMe6tP3RBnqjVw== X-Received: by 2002:a05:6214:c6c:b0:496:8e7:a93b with SMTP id t12-20020a0562140c6c00b0049608e7a93bmr1193772qvj.97.1660662601979; Tue, 16 Aug 2022 08:10:01 -0700 (PDT) Received: from maniforge.dhcp.thefacebook.com ([2620:10d:c091:480::a5ed]) by smtp.gmail.com with ESMTPSA id dm14-20020a05620a1d4e00b006bad20a6cfesm10794561qkb.102.2022.08.16.08.10.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Aug 2022 08:10:01 -0700 (PDT) Date: Tue, 16 Aug 2022 10:09:41 -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 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. Thanks, David