On Tue, 27 Aug 2002, Andi Kleen wrote:
>
> That is because of the lock it takes. Locks are always slow.
xtime_lock?
>
> Older kernels used gettimeoffset which ran without lock, but that was
> changed because in some very obscure cases it could cause non monotonous
> timestamps when the user turns on timestamp receiving to user space
> (kernel protocols do not care)
>
> Possibilities:
>
> - Ignore the problem and switch back to gettimeoffset again
Is it safe to call gettimeoffset without the lock?
> - Switch to gettimeoffset but add some correction step for the unlikely
> case that someone wants the timestamp from user space
> (would be my prefered solution)
> - Implement lockless gettimeofday like x86-64 or sparc
> (good one too, but likely slower than last)
ia64 seems to also have the lock.
cheers,
jamal
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