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 E2739C001DE for ; Thu, 10 Aug 2023 22:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231133AbjHJWqY (ORCPT ); Thu, 10 Aug 2023 18:46:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229718AbjHJWqV (ORCPT ); Thu, 10 Aug 2023 18:46:21 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAB07272E for ; Thu, 10 Aug 2023 15:46:20 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5897d05e878so18061217b3.3 for ; Thu, 10 Aug 2023 15:46:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1691707580; x=1692312380; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=xjd4vkpdCNZjHu9BtGW8X6WGb20e5wp6H/aYsqXsyEQ=; b=vuxVUQS/Rd+IBKBm1b7ikeBESL4jyxpR8mKK8cQmpQ+hmVJHXNQjOsb5p6NReTCEhM igBaQaVx6ysaNlCaP8vRvg3YEouXmY7Y+9yOdNEpgrMyk9kUzP5kQzNIgv5xJHtJdlwc kpW63jCiWVKAiyvbhJi6fXJZbABZguB1XML+0jfYC3kd5xeiOvQDwXMnUyyOFwJDmFfA DS7IVEibz0kQAN8dXFuPkmgDa8GIR7fHDANa362Jmqzwt01IxSo8b+kNKWy7wNCj1zNT Po/ySyBdBUGf2JhqrHxzwxht/rjqP0vn2uXGS0PtjW89+U8p9q35C+Oim+S6FawDN2Qq ze0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691707580; x=1692312380; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=xjd4vkpdCNZjHu9BtGW8X6WGb20e5wp6H/aYsqXsyEQ=; b=a10nh22238Ll6QYNWuCRjQXJhvHy/1ODjN9sMCpmK/vSXGG5e8aPHkkXC019kpqfNA 9u9UgFlqZzw1EkWfdJA15U76SNwFG20IavYs4HzOOM1FRcmlJPuQ5Awv2fADwZ3R3h80 1Xk6ZLPMk9dEBWqCcv4/JFd7HHXXRoozy2XqbYt8ks1ygP40PEYzaoomNvPPwOzHjH+a 6JJcYnafAvlsYkompfOCZYXSzN2HIpVcmLOuR2izUQouZ57hpSho23yMLFvS1XDjKBhE UdBV6GQCYqF+shqb3kpPWoDqU+nsMiB6qawItpLs0H6fD+TBP3naS6YZG0zDLRBOqH2S AZjQ== X-Gm-Message-State: AOJu0YyL7ymtLOBVM2M+T6O0fzAYlpmcy9r/3+gtAAe2HKC3bTiqo4TQ y2gqLb58EETeJBRUQtK/Zfj6cJ4= X-Google-Smtp-Source: AGHT+IGL0cU/OgNlmX6HF6UNubkpMQKosZNdhYWpVGifdB9x5uIbsl02rc0lbeMuVFPl9CKTW9Er8qg= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a81:b654:0:b0:586:a6e3:88cd with SMTP id h20-20020a81b654000000b00586a6e388cdmr6521ywk.5.1691707580066; Thu, 10 Aug 2023 15:46:20 -0700 (PDT) Date: Thu, 10 Aug 2023 15:46:18 -0700 In-Reply-To: <20230810220456.521517-1-void@manifault.com> Mime-Version: 1.0 References: <20230810220456.521517-1-void@manifault.com> Message-ID: Subject: Re: [PATCH bpf-next] bpf: Support default .validate() and .update() behavior for struct_ops links From: Stanislav Fomichev To: David Vernet Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, tj@kernel.org, clm@meta.com, thinker.li@gmail.com Content-Type: text/plain; charset="utf-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/10, David Vernet wrote: > Currently, if a struct_ops map is loaded with BPF_F_LINK, it must also > define the .validate() and .update() callbacks in its corresponding > struct bpf_struct_ops in the kernel. Enabling struct_ops link is useful > in its own right to ensure that the map is unloaded if an application > crashes. For example, with sched_ext, we want to automatically unload > the host-wide scheduler if the application crashes. We would likely > never support updating elements of a sched_ext struct_ops map, so we'd > have to implement these callbacks showing that they _can't_ support > element updates just to benefit from the basic lifetime management of > struct_ops links. > > Let's enable struct_ops maps to work with BPF_F_LINK even if they > haven't defined these callbacks, by assuming that a struct_ops map > element cannot be updated by default. Any reason this is not part of sched_ext series? As you mention, we don't seem to have such users in the three?