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=-3.7 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 61EC8C433DF for ; Tue, 13 Oct 2020 21:06:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AF2920EDD for ; Tue, 13 Oct 2020 21:06:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KQWyBL1B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727690AbgJMVGG (ORCPT ); Tue, 13 Oct 2020 17:06:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726652AbgJMVGG (ORCPT ); Tue, 13 Oct 2020 17:06:06 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15EDBC061755; Tue, 13 Oct 2020 14:06:05 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id t12so2327971ilh.3; Tue, 13 Oct 2020 14:06:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=C97h+MRq5l70WYEeMsIQX2bPmyCE0QOE/Kr9SYmuEek=; b=KQWyBL1B41rVXjsLWnmDO1jACfL2V7+8oLCS+mIdRxZHu+3UO/xKbs6/31FwUSQouW 3KLhYVndnILQx7Nh1uuKPyF8gfAL6s5H4WxAclBP+MjMr8QV03c5jwaCndPXEIeOLYlT XqfBdE97RWtX6ULuJwnzhmZTSvmRrqXYtvYK/i+gGOUxtYUDnFVb8CJTJh+FHPYBdNRC XJWrh7qzdDtKj9pbmQsq2X/6FvMUxeBTF/zZDyLfkYMlsKZBUlF602p1NGu2PTbQg4MB 17VB0huzr9Gc+9vCPUIakgKoecW7ZW1FZw/tzWwd1xu5XAAebJJ3SWwz72NlUiEocINj /bkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=C97h+MRq5l70WYEeMsIQX2bPmyCE0QOE/Kr9SYmuEek=; b=uh90g5gAHOJD2SC6nj5ad2YoiyHqsSgMzSy/DiivIknHN95ZljgC1QKA4Mjua7TnKs Saqb0KY6ltuRQNsdiPGDXFZHI6Ko3hMbzHrWRWE/7KqZbOhz4pxj+FHRzNTZN8d7xRHl al3XgaJs8lL3F2z+x9pU7xkRXyFV8o1xGVmocbV0tKIsdTwJTSaQcXmfm2/nRJZ0WBvq EKAbiXmhCktuEBD70gD6Iev9dZswaCpPL6ZWeomJIGxWYYtahPxM+s8UIQYV9ZJt4q+V dKwIVVx8m5kxLYBtS23TtVMy2u2bbiPVhVDBvaWXU4opbSiMi6vU4S0LPs38or6iVtQR TdKw== X-Gm-Message-State: AOAM532nE2YlAXOkvwuM2xlHiOZS7iSKAFlTj8GYsAzaO4Z7E26BfEG5 +RKw1Uu7KApoxMh1K1+/cAhpw/1sA/SKxQ== X-Google-Smtp-Source: ABdhPJxLMtd+8d4/MGijYt4mmj6QqmasAOS6bXUzHb1bvZ3sD09AhUUGlI2RMcuTnn639csE3kcmhg== X-Received: by 2002:a05:6e02:ef4:: with SMTP id j20mr1466194ilk.195.1602623164229; Tue, 13 Oct 2020 14:06:04 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id q196sm929652iod.17.2020.10.13.14.06.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Oct 2020 14:06:03 -0700 (PDT) Sender: Arvind Sankar From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Tue, 13 Oct 2020 17:06:02 -0400 To: Jens Axboe Cc: Linus Torvalds , io-uring , "linux-kernel@vger.kernel.org" Subject: Re: [GIT PULL] io_uring updates for 5.10-rc1 Message-ID: <20201013210602.GA1466033@rani.riverdale.lan> References: <36a6706d-73e1-64e7-f1f8-8f5ef246d3ea@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Tue, Oct 13, 2020 at 01:49:01PM -0600, Jens Axboe wrote: > On 10/13/20 1:46 PM, Linus Torvalds wrote: > > On Mon, Oct 12, 2020 at 6:46 AM Jens Axboe wrote: > >> > >> Here are the io_uring updates for 5.10. > > > > Very strange. My clang build gives a warning I've never seen before: > > > > /tmp/io_uring-dd40c4.s:26476: Warning: ignoring changed section > > attributes for .data..read_mostly > > > > and looking at what clang generates for the *.s file, it seems to be > > the "section" line in: > > > > .type io_op_defs,@object # @io_op_defs > > .section .data..read_mostly,"a",@progbits > > .p2align 4 > > > > I think it's the combination of "const" and "__read_mostly". > > > > I think the warning is sensible: how can a piece of data be both > > "const" and "__read_mostly"? If it's "const", then it's not "mostly" > > read - it had better be _always_ read. > > > > I'm letting it go, and I've pulled this (gcc doesn't complain), but > > please have a look. > > Huh weird, I'll take a look. FWIW, the construct isn't unique across > the kernel. > > What clang are you using? > > -- > Jens Axboe > If const and non-const __read_mostly appeared in the same file, both gcc and clang would give errors.