Re: Intel P6 vs P7 system call performance

H. Peter Anvin
2002-12-17T19:14:12Z

Linus Torvalds wrote:
>
> On Tue, 17 Dec 2002, Ulrich Drepper wrote:
>
>>But this is exactly what I expect to happen. If you want to implement
>>gettimeofday() at user-level you need to modify the page.
>
> Note that I really don't think we ever want to do the user-level
> gettimeofday(). The complexity just argues against it, it's better to try
> to make system calls be cheap enough that you really don't care.
>

Let's see... it works fine on UP and on *most* SMP, and on the ones
where it doesn't work you just fill in a system call into the vsyscall
slot. It just means that gettimeofday() needs a different vsyscall slot.

-hpa