From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Time resolution in Emacs Date: Mon, 25 Apr 2022 12:27:41 -0700 Organization: UCLA Computer Science Department Message-ID: References: <5ed963b2-3fa8-48d8-627e-bc0571d15b43@gmail.com> <4a23f3a4-fe8f-d396-49d8-10034803be63@gmail.com> <52fb10fb-892a-f273-3be8-28793f27e204@cs.ucla.edu> <5cd820d4-ae67-43d4-9e63-c284d51ff1e4@gmail.com> <83tuapvcxs.fsf@gnu.org> <6efc5d24-34a2-fd30-cd20-fe4ac3e48310@cs.ucla.edu> <83fsm8tdzl.fsf@gnu.org> <9e4781b2-2ffa-b1ce-09b4-ead82cad9038@cs.ucla.edu> <83ilr3siku.fsf@gnu.org> <4e41671c-fae8-61c4-845c-4c7ba4317e88@cs.ucla.edu> <83fsm7sh2s.fsf@gnu.org> <83czhbsgc2.fsf@gnu.org> <33fb24fb-282b-cc13-a597-e7b63f19982d@cs.ucla.edu> <83y1zzq6kd.fsf@gnu.org> <837d7hr8s3.fsf@gnu.org> <83h76kq5c6.fsf@gnu.org> <9afbcc3d-b57c-b5bf-e4f6-52b352f99af8@cs.ucla.edu> <83bkwspa1r.fsf@gnu.org> <3008dea1-572b-9010-f3c4-15272145fd8a@cs.ucla.edu> <7ae621ed-d03b-00cd-bfb3-04a4a2a7d5ce@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="34398"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Cc: Eli Zaretskii , emacs-devel@gnu.org To: Max Nikulin Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Apr 25 21:28:40 2022 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nj4O0-0008jd-4k for ged-emacs-devel@m.gmane-mx.org; Mon, 25 Apr 2022 21:28:40 +0200 Original-Received: from localhost ([::1]:49182 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nj4Ny-00089E-JX for ged-emacs-devel@m.gmane-mx.org; Mon, 25 Apr 2022 15:28:38 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52424) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nj4NB-0007US-Ge for emacs-devel@gnu.org; Mon, 25 Apr 2022 15:27:49 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:40836) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nj4N9-0002o4-2A; Mon, 25 Apr 2022 15:27:48 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 7B8911600E5; Mon, 25 Apr 2022 12:27:43 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id UU_j28YCm0Ue; Mon, 25 Apr 2022 12:27:42 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 9A1881600EB; Mon, 25 Apr 2022 12:27:42 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id FB7b3anPW8gA; Mon, 25 Apr 2022 12:27:42 -0700 (PDT) Original-Received: from [131.179.64.200] (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 642BF1600E5; Mon, 25 Apr 2022 12:27:42 -0700 (PDT) Content-Language: en-US In-Reply-To: <7ae621ed-d03b-00cd-bfb3-04a4a2a7d5ce@gmail.com> Received-SPF: pass client-ip=131.179.128.68; envelope-from=eggert@cs.ucla.edu; helo=zimbra.cs.ucla.edu X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:288876 Archived-At: On 4/25/22 09:54, Max Nikulin wrote: > on Linux while file metadata are in cache, timestamps may > have high time resolution. When later fetched from disk they may have > coarse resolution, e.g. whole seconds. Yes, that is a known bug in older Linux kernels. As I understand it, the bug was fixed many years ago. (It broke GCC builds circa 2004[1] so there was a good deal of motivation to fix it.) I expect this problem is no longer relevant; if I'm wrong, Eli's suggestion would help to work around it. [1]: https://linux.kernel.narkive.com/XLtQbTzQ/linux-2-6-nanosecond-time-stamp-weirdness-breaks-gcc-build