From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753442AbZBHS0D (ORCPT ); Sun, 8 Feb 2009 13:26:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753074AbZBHSZx (ORCPT ); Sun, 8 Feb 2009 13:25:53 -0500 Received: from wa-out-1112.google.com ([209.85.146.177]:44868 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988AbZBHSZw (ORCPT ); Sun, 8 Feb 2009 13:25:52 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:date:message-id:subject:from:to:cc :content-type:content-transfer-encoding; b=OMjOUX6VPe87yBTcwJCPb2OpzUYFdIL7LdaxwrpIkUzFkrdw842LfHrbyQk2IhUvAv JSAQK8xmZTaHOJ5xd/xLDd0x7XRNdeAnCRrDxcLJyixv8Qd+8BsLvGLYOAIcxKD3J6Sg mATG5kEhMmPZ5eQmgtayQxVVzxBgcbQXVIJEE= MIME-Version: 1.0 Reply-To: mtk.manpages@gmail.com Date: Mon, 9 Feb 2009 07:25:50 +1300 Message-ID: Subject: Why does timerfd() only support CLOCK_REALTIME and CLOCK_MONOTONIC? From: Michael Kerrisk To: Davide Libenzi Cc: "linux-man@vger.kernel.org" , lkml , Thomas Gleixner Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Davide, At the moment I'm looking into writing man pages for timer_create(2) and friends. (Somewhat bizarrely, these pages do not yet exist.) As I looked into the source code of timer_create(), etc., and did some tests, I saw that timer_create() supports the following clocks: TIMER_REALTIME TIMER_MONOTONIC TIMER_PROCESS_CPUTIME_ID TIMER_THREAD_CPUTIME_ID clockid obtained from clock_getcpuclockid(3) clockid obtained from pthread_getcpuclockid(3) On the other hand, timerfd() only permits the first two of these. What's the reason for that limitation of timerfd()? (It may be worth adding something to the man page on this point.) Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html