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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A4A11C433DB for ; Fri, 15 Jan 2021 03:24:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A32523AC6 for ; Fri, 15 Jan 2021 03:24:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726518AbhAODYZ (ORCPT ); Thu, 14 Jan 2021 22:24:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726405AbhAODYZ (ORCPT ); Thu, 14 Jan 2021 22:24:25 -0500 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE59BC061575; Thu, 14 Jan 2021 19:23:44 -0800 (PST) Received: by mail-lf1-x12b.google.com with SMTP id o17so11192810lfg.4; Thu, 14 Jan 2021 19:23:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=8bof/9UT0KgyjHC36RQ3/jNqdyR1Op8Ft0YEcB0dzb8=; b=saGWmQcv7f4npbnhTNj89g/8kMaCmow5jNC6kG6vY7q0X7VjkQ28fjpeAQF+xjL8cK XqPetTGA44jcNTZMTA58sxbVMYQO20r2RZmGTb58yE1zF33Soz3is0FT8Vz+TPzUyBeZ aAWI/8qgRoOqCP0aJqhtjFVrl2EhiW4erVYlH9LoywQOabwaHrmaJHWzI/Judp0LEUCO T5FAMuD/Mm+GsjJ0XlkRcvU80I+e/WTzhFyaOLbn2GKEMTq7xhBqFDt0AEneyuSFvYDB g8SlKsRwbrgEjfBxnHZcU3OjmG7l5nM3s6oZfRrpByux6xGIa7Y+Zdxu383NSet8efnZ Wrpg== 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=8bof/9UT0KgyjHC36RQ3/jNqdyR1Op8Ft0YEcB0dzb8=; b=h24OkO7Obj0gfPoik3CpN12fD+Ei3QSMspS+SVOzCu7cqyQaI1oqgSMU7aC04sD5k6 ZOwOULwqxK5Vgx8gaKdjeAxxohNibUvF9Jq9e5gtok+gJ6oiq0zuOtrshmONo3EOuypE wh7hihJ02OFcLNpeLmwNAC8hi4BanbNmoXK0467qaKke/cUkV+JR/2wUbVdmI6dOVnOm cjljU7YSidDbagswgghpZjPzHiFqnJo+h+oaA6P4sNxY0LLZZpk2g0D/MtkiW/hoPXSU mYfApH0KwjU4ibou6iSSWTegkZrCCxVetrCdfnlsiy0yPc06OPVidLgZx0w8SsxFH5e2 lEng== X-Gm-Message-State: AOAM530BvPGFqeeW4DchNx0dLEQXSq08YjuB2U7CaVuLI0BwLNcxNdUW kj/1f8Iho9sim+34j78bgwizkNw0sREHlF7txpg= X-Google-Smtp-Source: ABdhPJwLtb8FK71GrQRyVoDSXloI3NLRe5oRlaoEK+WgSH5AKXF2H9nzJfX70g53mufw/iNddSvd9VJsnStxB5c1evw= X-Received: by 2002:ac2:5b1e:: with SMTP id v30mr5088387lfn.540.1610681023413; Thu, 14 Jan 2021 19:23:43 -0800 (PST) MIME-Version: 1.0 References: <20210114181751.768687-1-jackmanb@google.com> In-Reply-To: <20210114181751.768687-1-jackmanb@google.com> From: Alexei Starovoitov Date: Thu, 14 Jan 2021 19:23:32 -0800 Message-ID: Subject: Re: [PATCH bpf-next v7 00/11] Atomics for eBPF To: Brendan Jackman Cc: bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , KP Singh , Florent Revest , LKML , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , John Fastabend , Yonghong Song Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Jan 14, 2021 at 10:18 AM Brendan Jackman wrote: > > There's still one unresolved review comment from John[3] which I > will resolve with a followup patch. > > Differences from v6->v7 [1]: > > * Fixed riscv build error detected by 0-day robot. Applied. Thanks a lot. Please address John's request in a followup and these few issues: - rst doesn't look correct. Example: rst2man Documentation/networking/filter.rst >/dev/null Documentation/networking/filter.rst:1053: (WARNING/2) Inline emphasis start-string without end-string. > Except ``BPF_ADD`` _without_ ``BPF_FETCH`` (for legacy reasons), all 4 byte > atomic operations require alu32 mode. Clang enables this mode by default in > architecture v3 (``-mcpu=v3``). For older versions it can be enabled with > ``-Xclang -target-feature -Xclang +alu32``. It reads confusing to me. I would rephrase 'clang enables this mode by default' into 'clang can generate new atomic instruction when -mcpu=v3 is enabled'. 'For older versions...' This part I didn't get. The users need clang 12 that is capable to emit these insns. What 'older versions' you're talking about?