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From: John Stultz <john.stultz@linaro.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Arun Sharma <asharma@fb.com>, LKML <linux-kernel@vger.kernel.org>,
	Kumar Sundararajan <kumar@fb.com>,
	Richard Cochran <richardcochran@gmail.com>
Subject: Re: clock_gettime_ns
Date: Wed, 04 Sep 2013 13:50:31 -0700	[thread overview]
Message-ID: <52279D17.2010607@linaro.org> (raw)
In-Reply-To: <CALCETrVdAGbp-ogvideZ6GiDVu8W3v+6Z=hJSrr+62U50HG8wg@mail.gmail.com>

On 09/04/2013 01:23 PM, Andy Lutomirski wrote:
> On Wed, Sep 4, 2013 at 12:17 PM, John Stultz <john.stultz@linaro.org> wrote:
>> On Wed, Sep 4, 2013 at 2:18 AM, Arun Sharma <asharma@fb.com> wrote:
>>> A couple of years ago Andy posted this patch series:
>>>
>>> http://thread.gmane.org/gmane.linux.kernel/1233209/
>>>
>>> These patches have been in use at facebook for a couple of years and along
>>> with a vDSO implementation of thread_cpu_time(), they have proven useful for
>>> our profilers.
>>>
>>> I didn't see any arguments against this patch series. Did I miss some
>>> discussion on the topic?
>> (I've got a new email address, just fyi)
>>
>> So, looking at the thread, I think Richard brought up the issue that
>> the net performance gain with the new interface wasn't significant
>> after the optimizations were applied to both interfaces.
>>
>> If we're going to add a new interface that uses something other then a
>> timespec, we likely need to put some serious thought into that new
>> type, and see how it could be used across a number of syscalls. Some
>> of the discussion around dealing with the 2038 issue touched on this.
>>
>> But getting those optimizations to the existing interface merged would
>> be nice, though.  Anyone want to resend the patch?
> It's already in.  See 5f293474c4c6c4dc2baaf2dfd486748b5986de76, etc.
Great!
-john


  reply	other threads:[~2013-09-04 20:50 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-04  9:18 clock_gettime_ns Arun Sharma
2013-09-04 18:51 ` clock_gettime_ns Andy Lutomirski
2013-09-04 19:20   ` clock_gettime_ns John Stultz
2013-09-04 20:33     ` clock_gettime_ns Andy Lutomirski
2013-09-04 20:54       ` clock_gettime_ns John Stultz
2013-09-04 22:29         ` clock_gettime_ns H. Peter Anvin
2013-09-04 22:59           ` clock_gettime_ns John Stultz
2013-09-04 23:04             ` clock_gettime_ns H. Peter Anvin
2013-09-04 23:20               ` clock_gettime_ns John Stultz
2013-09-04 23:38           ` clock_gettime_ns Andy Lutomirski
2013-09-05  1:22             ` clock_gettime_ns H. Peter Anvin
2013-09-09 17:47               ` clock_gettime_ns Andy Lutomirski
2013-09-11 18:50                 ` clock_gettime_ns Richard Cochran
2013-09-04 19:17 ` clock_gettime_ns John Stultz
2013-09-04 20:23   ` clock_gettime_ns Andy Lutomirski
2013-09-04 20:50     ` John Stultz [this message]
2013-09-05  4:45   ` clock_gettime_ns Arun Sharma

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