Re: [net-next PATCH v2 5/8] net: Track start of busy loop instead of when it should end

On Thu, 2017-03-23 at 14:37 -0700, Alexander Duyck wrote:

From: Alexander Duyck <redacted>

The last bit I changed is to move from using a shift by 10 to just using
NSEC_PER_USEC and using multiplication for any run time calculations and
division for a few compile time ones.  This should be more accurate and
perform about the same on most architectures since modern CPUs typically
handle multiplication without too much overhead.

busy polling thread can be preempted for more than 2 seconds.

Using usec instead of nanoseconds gave us 3 orders of magnitude cushion.

We do not need nsec accuracy for busy polling users, if this restricts
range and usability under stress.