Re: [patch] fastcall-2.3.32-B6, SYSENTER/SYSEXIT support

Linus Torvalds (torvalds@transmeta.com)
Tue, 14 Dec 1999 10:45:33 -0800 (PST)


On Sun, 12 Dec 1999, Pavel Machek wrote:
> >
> > Who cares how fast you can do "getpid()"? NOBODY. It's meaningless.
>
> Well, read from cached file is _not_ meaningless, still Ingo seen
> improvements on that.

Not really.

You see improvements on the order of a percent or two IFF:
- you do small reads
- in a tight loop

Ergo, that benchmark was really not worth it either.

> I think you should concentrate on read(), write() and select()
> syscalls. Those are the ones done often.

I mostly agree, although gettimeofday() under X is actually _the_ most
common one. But gettimeofday() is special anyway, simply because it
doesn't actually need to do a kernel entry, so the three you mention are
certainly "basic".

Linus

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