Re: Intel P6 vs P7 system call performance

Richard B. Johnson (root@chaos.analogic.com)
Tue, 17 Dec 2002 12:13:04 -0500 (EST)


On Tue, 17 Dec 2002, Manfred Spraul wrote:

> >
> >
> > pushl %ebp
> > movl $0xfffff000, %ebp
> > call *%ebp
> > popl %ebp
> >
> >
>
> You could avoid clobbering a register with something like
>
> pushl $0xfffff000
> call *(%esp)
> addl %esp,4
>

This is a near 'call'.

pushl $0xfffff000
ret

This is a 'far' 'call' that I think you will need to reload the segment
back to user-mode segments on the return.

pushl $KERNEL_CS
pushl $0xfffff000
lret

Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.

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