Timers and timing, was: MySQL Performance 6.0rc1

[David Xu]

Poul-Henning Kamp wrote:
> In message <4361FDBE.7000500 at freebsd.org>, David Xu writes:
> 
> 
> the correct way to optimize this would be to add a time(2) systemcall
> which returns the value of the kernel global time_second.
> 

Can we make a page in kernel address space which is readable my user
code? put the variable in the page, I know read an integer is atomic-op,
needn't lock, so syscall is not needed.