Re: Intel P6 vs P7 system call performance

Ulrich Drepper
2002-12-17T18:50:38Z

Alan Cox wrote:

> getppid changes and so I think has to go to kernel (unless we go around
> patching user pages on process exit [ick]).

But this is exactly what I expect to happen. If you want to implement
gettimeofday() at user-level you need to modify the page. Some of the
information the kernel has to keep for the thread group can be stored in
this place and eventually be used by some uerlevel code executed by
jumping to 0xfffff000 or whatever the address is.

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