From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [Y2038] [PATCH 04/11] posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure Date: Wed, 22 Apr 2015 12:11:14 +0200 Message-ID: <20150422101114.GA5527@localhost.localdomain> References: <1429509459-17068-1-git-send-email-baolin.wang@linaro.org> <3231171.5TrYVVBLh4@wuerfel> <2819798.f0KhjY3UAe@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Arnd Bergmann , y2038@lists.linaro.org, Baolin Wang , pang.xunlei@linaro.org, Peter Zijlstra , Benjamin Herrenschmidt , Heiko Carstens , Paul Mackerras , cl@linux.com, heenasirwani@gmail.com, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, mpe@ellerman.id.au, rafael.j.wysocki@intel.com, ahh@google.com, Frederic Weisbecker , pjt@google.com, riel@redhat.com, Martin Schwidefsky , John Stultz , rth@twiddle.net, gregkh@linuxfoundation.org, LKML , netdev@vger.kernel.org, Tejun Heo , linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org, Ingo Molnar , "Paul E. McKenney" To: Thomas Gleixner Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Apr 22, 2015 at 10:45:23AM +0200, Thomas Gleixner wrote: > So we could save one translation step if we implement new syscalls > which have a scalar nsec interface instead of the timespec/timeval > cruft and let user space do the translation to whatever it wants. +1 > I personally would welcome such an interface as it makes user space > programming simpler. Just (re)arming a periodic nanosleep based on > absolute expiry time is horrible stupid today: Jup. > Thoughts? Current user space example: The linuxptp programs are doing ns64 to timespec conversions to call into the kernel, which then does timespec to ns64 to talk to the hardware. I would bet that most (all?) use cases are better served with 64 bit nanosecond system calls. Thanks, Richard