Re: Intel P6 vs P7 system call performance

[H. Peter Anvin]

Linus Torvalds wrote:
> 
> On Tue, 17 Dec 2002, Linus Torvalds wrote:
> 
>>Hmm.. Which system calls have all six parameters? I'll have to see if I
>>can find any way to make those use the new interface too.
> 
> 
> The only ones I found from a quick grep are
>  - sys_recvfrom
>  - sys_sendto
>  - sys_mmap2()
>  - sys_ipc()
> 
> and none of them are of a kind where the system call entry itself is the
> biggest performance issue (and sys_ipc() is deprecated anyway), so it's
> probably acceptable to just use the old interface for them.
> 

recvfrom() and sendto() can also be implemeted as sendmsg() recvmsg() if
one really wants to.

What one can also do is that a sixth argument, if one exists, is passed
on the stack (i.e. in (%ebp), since %ebp contains the stack pointer.)

	-hpa