Bernd Walter wrote: >On Fri, Oct 28, 2005 at 06:43:10PM +0800, David Xu wrote: > > >>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. >> >> > >Don't whink it is importent for 1s intervalls, but atomic != coherent. > > > That's just an idea. :-) As robert said, add a lower resolution CLOCK_ type may work well. Another thing I just though of, if reading timercounter is so slow, won't gettimeofday hardly block cpu too many cycles ? the cpu is just stucked there by a slow clock in hardware signals.Received on Fri Oct 28 2005 - 11:26:07 UTC
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