On Fri, Feb 18, 2011 at 12:07 PM, erik quanstrom <[email protected]> wrote:
>> The high level overview is that it is stored in a shared page, mapped
>> into each new process's memory space at start-up. The kernel is never
>> entered; there are no context switches. The kernel has a timer that
>> updates this page atomically.
>
> i wonder if that is uniformly faster. consider that
> making reads of that page coherent enough on a
> big multiprocessor and making sure there's not too
> much interprocesser skew might be slower than a
> system call.
are you claiming that
enter system call
look at kernel data page to figure out time
exit system call
could be faster than
look at kernel data page to figure out time
?
either way the memory accesses in the middle
are the same.
