From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752794AbcIINsn (ORCPT ); Fri, 9 Sep 2016 09:48:43 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:48787 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751126AbcIINsl (ORCPT ); Fri, 9 Sep 2016 09:48:41 -0400 Date: Fri, 9 Sep 2016 15:46:13 +0200 (CEST) From: Thomas Gleixner To: Richard Cochran cc: John Stultz , Nicolas Pitre , Josh Triplett , lkml Subject: Re: [RFC/PATCH] posix-timers: make them configurable In-Reply-To: <20160909074857.GA9083@localhost.localdomain> Message-ID: References: <20160909074857.GA9083@localhost.localdomain> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 9 Sep 2016, Richard Cochran wrote: > On Thu, Sep 08, 2016 at 02:19:24PM -0700, John Stultz wrote: > > Also given many other syscalls take clockids and the backing logic > > isn't really getting removed (probably could cut the dynamic posix > > clocks core with the same conditional), I wonder if you could get a > > similar size win by taking a slightly more narrow cutting of the > > subsystem. That way you could preserve the more useful clock_gettime() > > functionality, but maybe stub out some of the less often used > > functionality. > > I want to support tinification, but I also doubt the utility of > removing clock_gettime() and clock_nanosleep(). I can't imagine ever > building a user space without those. In fact, thinking about IoT, > having good time is critical, and so these are the *last* functions I > would remove when downsizing. gettimeofday() gives you microsecond resolution which is good enough for 99.9% of all problems. The only real downside is removing clock_nanosleep() because nanosleep() does not give you the ability to schedule timers on absolute time. Thanks, tglx