Configure timer slack for 1 second

[gaul]

This allows the kernel scheduler to coalesce wakeups, improving
battery life. Linux defaults to 50 ms slack. Reference:

http://lwn.net/Articles/369549/

[dgraziotin]

Thanks for this, and for the link. The tests pass, everything seems to be working well. Before merging this, I have a couple questions (mostly because I am no expert here):

• Does Linux default to 50ms in all (recent) versions?
• Isn't prctl expecting arg2 to be in nanoseconds?
  • If I got it right, 1000 * 1000 nanoseconds = 1 millisecond = 0.001 seconds. But your commit message claims to change the timer slack to 1 second. I am confused at this point :-)

[gaul]

I corrected arg2 to be 1000 * 1000 * 1000 nsec, or 1 sec. man prctl in Linux 3.13 documents the default at 50 msec.

[sasanj]

As per man prctl, the sleep function is not affected, so we should use something like nanosleep, which is addressed in pull request #130.
As a side note, the sleep man page, mentions that in Linux, this function is implemented using nanosleep.
However using nanosleep seems better and safer.

[dgraziotin]

@gaul do you have any comments about @sasanj suggestion for this one?

[dgraziotin]

aaand I missed out the other PR. Closing this one. Thanks!

[gaul]

Please reopen, this works in conjunction with #130.