From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.6 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RCVD_IN_SORBS_SPAM, RP_MATCHES_RCVD,T_DKIM_INVALID shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 0C6AD20193 for ; Thu, 27 Oct 2016 23:09:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942655AbcJ0XJm (ORCPT ); Thu, 27 Oct 2016 19:09:42 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:32859 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933978AbcJ0XJl (ORCPT ); Thu, 27 Oct 2016 19:09:41 -0400 Received: by mail-oi0-f66.google.com with SMTP id i127so211817oia.0 for ; Thu, 27 Oct 2016 16:09:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=Nvg/vltQWmE0kw9zzN7zS1IpxumR+o2bNTkx+jtSSZo=; b=QJb0hTykvhlvmzcYYhuX+gHYlkNN2ZmzMTZkQ7YUgoIXhN+sgK+w8uNJcJ00nKOrZ6 aCzK5AgOhzkhF6tBY6Yh+JTesAJr8SFGfePDb7yQA5f01244vzHBobkYswU2xiCYSOtd pqCRoc6CLzYlT9kw+pwKhhP275er8RMSFsnrBrBLzqot7hxloX/xZYVpKoPYebTEs/Sc YBvvCkN4wYF9JJ/HWjns7mOqAwuUVoiPp7K7i3hPdEnvMkVk89r4MKn+ovq285tbysPE KL8D9BNwvBGZWfTdoWmlIOmvM+94g4vAq1k+c9c66XPp6uvcnF3giNMKomdypikbrjCn 8XzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=Nvg/vltQWmE0kw9zzN7zS1IpxumR+o2bNTkx+jtSSZo=; b=W0Xr+Ym+Fubg2mlIK4/cbgC+60C5IObnTlam7u4Sh5U+fTFz6jbkfljvLAE5M2y0Yb E3kvrzAnsDduUX+D6qZmX0OoYHJQcMvdfwO0A2Y/zs4I/8bsXL2KICNZzvc6RRiZkW2c 3jQEHfEpkBl/+y9sSx1ptd615mayS8pUe7xac0ma0xBs9bhMeHV/BO3nuwdGc3CgY4Ed 9CVCmVd8iKSDbdbQo95UXInaawJUKhg4rWuv4i6PH0gmz1KQ3A9NyJmqAQmBUE9xJY9I 93Nj8fZYr+5xdqq0rsdDXPWkirgzVg0KZ0GzzVc+PmzRV6PofxrJe82NZsSrol2/C66m 6rYg== X-Gm-Message-State: ABUngveYNRjWKcLCaLlsO+8l3LI/VaO/cY62Rb9LRIK5KZJS9c+0f+As4MyMm/hEMVEuutcNPPFbhpT5Zhi6rg== X-Received: by 10.157.39.2 with SMTP id r2mr8505190ota.103.1477609780480; Thu, 27 Oct 2016 16:09:40 -0700 (PDT) MIME-Version: 1.0 Received: by 10.182.142.104 with HTTP; Thu, 27 Oct 2016 16:09:39 -0700 (PDT) In-Reply-To: References: <20161025181621.4201-1-gitster@pobox.com> <20161025181621.4201-3-gitster@pobox.com> <20161026042555.neaxvnmggtcku5cc@sigill.intra.peff.net> <20161026164746.2fu57f4pji5qdtnh@sigill.intra.peff.net> <20161026201721.2pw4slsuyhxhcwxj@sigill.intra.peff.net> <20161027102419.dbzigj7wtr355ofh@sigill.intra.peff.net> From: Linus Torvalds Date: Thu, 27 Oct 2016 16:09:39 -0700 X-Google-Sender-Auth: QhE8t3FmkRpFhWN6Asw6UmYbYvE Message-ID: Subject: Re: [PATCH v3 2/3] sha1_file: open window into packfiles with O_CLOEXEC To: Junio C Hamano Cc: Jeff King , Git Mailing List , Lars Schneider , Eric Wong , Johannes Schindelin Content-Type: text/plain; charset=UTF-8 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Thu, Oct 27, 2016 at 3:56 PM, Junio C Hamano wrote: > > I also thought O_NOATIME shouldn't be an effective fcntl(2) thing, > for the reasons you stated above, when I was studying the area > because of the discussion on these patches. I was surprised to see > that http://man7.org/linux/man-pages/man2/fcntl.2.html contradicts > by saying F_SETFL can take O_NOATIME. > > Perhaps it deserves a bugreport? It's not a bug per se. You can indeed change O_NOATIME with F_SETFL. And it actually does matter, since atime is normally changed by mmap(), read() and write() calls. So F_SETFL O_NOATIME actually does make sense, but it doesn't cover the atime update done by open() itself. That said, now that I think about it, I should double-check: maybe open() doesn't actually set atime at all, and we *could* do NOATIME with SETFL after all. The exact [acm]time semantics are damn subtle. Linus