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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 CB0B9C43331 for ; Thu, 26 Mar 2020 08:46:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D68F20714 for ; Thu, 26 Mar 2020 08:46:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="byNNdgBN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726270AbgCZIqj (ORCPT ); Thu, 26 Mar 2020 04:46:39 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:39530 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726210AbgCZIqj (ORCPT ); Thu, 26 Mar 2020 04:46:39 -0400 Received: by mail-wr1-f66.google.com with SMTP id p10so6659609wrt.6 for ; Thu, 26 Mar 2020 01:46:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=cc:subject:to:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Diaj29BCs1YmCsXUjORvzik0SNiu8r2iYyEM6mKeaoM=; b=byNNdgBN7yRL6nfMPUtaUsBQoFPBaE1+kQ8Se9z/sirSPhcygkqDBOF/aeteE2V8eW Hw0sf+gnWN45UktM8QlGrOABAVO23/oMP+I8sCHq8SFMQ/B823z0sebOZkAutOfArxI6 7AO6W+0pRsCz/dmjRzUioX26Cv92f0vGulAVhFmI3gZdTtBsF+eKXTzUpq4LDpsTlx/G MC5C2xxYT+xzTWMZSmIAJy4V/Z+VgiCuIKthVT1RBEvHR3354I/crga5Xd0G/HbuY9jY tPhPaiJv5dM0uzRGwsgN3dyM2ded+xYvn6cR0SOo0KClxQh6B93RuRGY+eAvoVyLutRL wuWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:cc:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Diaj29BCs1YmCsXUjORvzik0SNiu8r2iYyEM6mKeaoM=; b=PJxWjqNe8DPZ47jCDPf233HvmYaenEmSMm+R0KlE+E0FLW2ThAf2sJByGyZALOcEEy 8GdLl6lQFzLCo7MnHb11HtHOS4JZ7IXP0B7AbxCwBoF078etDgqajzZhlpMysQ9qxUky DGM39lc+WgZensTP3aTFLH/blKb6x13NCDgO+E8NMurn8FkOmb3GTUQXby7OonETsF/H yP6PrkVXuJuVM8juWA33j9jUG7ocWYRdTjUx+GEd7t5ejo70Ue34w3/gTTubp8lDLGOa SyOUn4e3GI9JzFCQZAQMQJRq5y1W/Q4lO5S5nymJIh4sdY7RMCzy3W56I49iosabKeZ3 R4BQ== X-Gm-Message-State: ANhLgQ2wFg2KSLk9xBU9bMxkcKJOsknzmC4TR/F5mNBGb3pOdznnDML+ GgWqIA54A8+OK6cWFbBaUcMaiFsy X-Google-Smtp-Source: ADFU+vuL1+e+DaGLt3wFqZIySQ0ZdbIYvwXTwwAPHaCUwG1Ce5H0BjfN1sC6ShgdMTz5323FqzcoTA== X-Received: by 2002:adf:fdd2:: with SMTP id i18mr5887670wrs.165.1585212397305; Thu, 26 Mar 2020 01:46:37 -0700 (PDT) Received: from ?IPv6:2001:a61:2482:101:3351:6160:8173:cc31? ([2001:a61:2482:101:3351:6160:8173:cc31]) by smtp.gmail.com with ESMTPSA id i19sm2613518wmb.44.2020.03.26.01.46.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Mar 2020 01:46:36 -0700 (PDT) Cc: mtk.manpages@gmail.com, linux-man@vger.kernel.org Subject: Re: [PATCH] timerfd_create.2: Included return value 0 To: "devi R.K" References: From: "Michael Kerrisk (man-pages)" Message-ID: <55aa30be-5894-ae52-ffd4-5f2a82aa5ad5@gmail.com> Date: Thu, 26 Mar 2020 09:45:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Hello Devi, On 3/18/20 3:04 PM, devi R.K wrote: > Added a return value 0 for timerfd_read which happens when there is a > bigger backward time drift*.* > > Signed-off-by: DEVI RK Can you say some more please about how you verified this and/or point me at the relevant kernel source code? At a simple attempt, I can't replicate the behavior you describe. Thanks, Michael > --- > man2/timerfd_create.2 | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/man2/timerfd_create.2 b/man2/timerfd_create.2 > index 066e0be..ccced98 100644 > --- a/man2/timerfd_create.2 > +++ b/man2/timerfd_create.2 > @@ -317,6 +317,10 @@ fails with the error > if the real-time clock undergoes a discontinuous change. > (This allows the reading application to discover > such discontinuous changes to the clock.) > +.IP > +A > +.BR read (2) > +may return 0 if the system clock undergoes a discontinuous change. > .TP > .BR poll "(2), " select "(2) (and similar)" > The file descriptor is readable > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/