Re: [PATCH 03/34] include: copy unlocked-io.h from gnulib

Sami Kerola
2013-07-09T06:37:27Z

On 8 July 2013 21:21, Kay Sievers <kay@vrfy.org> wrote:
> On Sun, Jul 7, 2013 at 9:54 PM, Sami Kerola <kerolasa@iki.fi> wrote:
>> At the moment util-linux command are not threading, which means they can
>> safely use thread-unsafe IO system calls which should make printing
>> quicker.
>
> Do you have numbers about the assumption that this will produce better
> results on Linux?
>
> Uncontended mutexes/futexes on Linux probably might not really show
> up. Maybe in inner loops, not sure. Would be nice to know ...

I did not do much testing, and to be honest results were slightly
disappointing. With simple 'time command < big_file' most of the
commands did not show measurable difference, but as a junior
programmer I thought the _unlocked would be beneficial for single
thread programs. As such assumptions are not preferred I will set up
some sort of test, which will try to accomplish what is the difference
of each locked vs _unlocked function call with various output sizes.
Assuming I get the test right it should not be a big deal to run it on
various systems I have access.

Karel could you hold these patches until there is more substance to
justify merge or reject.

--
Sami Kerola