Re: Intel P6 vs P7 system call performance

[H. Peter Anvin]

Matti Aarnio wrote:
> (cutting down To:/Cc:)
> 
> On Tue, Dec 17, 2002 at 11:43:57AM -0800, H. Peter Anvin wrote:
> 
>>Linus Torvalds wrote:
>>
>>>The thing is, gettimeofday() isn't _that_ special. It's just not worth a
>>>vsyscall of it's own, I feel. Where do you stop? Do we do getpid() too?
>>>Just because we can?
>>
>>getpid() could be implemented in userspace, but not via vsyscalls
>>(instead it could be passed in the ELF data area at process start.)
> 
> 
>   After fork() or clone()  ?
>   If we had only spawn(), and some separate way to start threads...
> 

fork() and clone() would have to return the self-pid as an auxilliary
return value.  This, of course, is getting rather fuggly.

Anything that cares caches getpid() anyway.

	-hpa