Re: Intel P6 vs P7 system call performance

H. Peter Anvin
2002-12-17T19:24:49Z

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