Date: Wed, 22 Apr 2015 12:11:14 +0200
From: Richard Cochran <richardcochran@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>, y2038@lists.linaro.org,
        Baolin Wang <baolin.wang@linaro.org>, pang.xunlei@linaro.org,
        Peter Zijlstra <peterz@infradead.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Paul Mackerras <paulus@samba.org>, 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 <fweisbec@gmail.com>, pjt@google.com,
        riel@redhat.com, Martin Schwidefsky <schwidefsky@de.ibm.com>,
        John Stultz <john.stultz@linaro.org>, rth@twiddle.net,
        gregkh@linuxfoundation.org, LKML <linux-kernel@vger.kernel.org>,
        netdev@vger.kernel.org, Tejun Heo <tj@kernel.org>, linux390@de.ibm.com,
        linuxppc-dev@lists.ozlabs.org, Ingo Molnar <mingo@kernel.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [Y2038] [PATCH 04/11] posix timers:Introduce the 64bit methods
 with timespec64 type for k_clock structure
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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
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