Re: [PATCH] Re: futex and timeouts

Hubertus Franke (frankeh@watson.ibm.com)
Fri, 15 Mar 2002 10:16:02 -0500

On Friday 15 March 2002 01:08 am, Joel Becker wrote:
> On Fri, Mar 15, 2002 at 04:39:50PM +1100, Rusty Russell wrote:
> > Yep, sorry, my mistake. I suggest make it a relative "struct timespec
> > *" (more futureproof that timeval). It would make sense to split the
> > interface into futex_down and futex_up syuscalls, since futex_up
> > doesn't need a timeout arg, but I haven't for the moment.
>
> Why waste a syscall? The user is going to be using a library
> wrapper. They don't have to know that futex_up() calls sys_futex(futex,
> FUTEX_UP, NULL);
>
> Joel

I agree with that, only for the reason that we are getting scarce on
syscall nubmers. Is 256-delta the max ?
On the other hand, it requires to always push 2 more arguments
(operand and useless parameter).

One thing to consider is that many don't want to use libraries.
They want to inline, which would result only in a few instruction.

What I would like to see is an interface that lets me pass optional
parameters to the syscall interface, so I can call with different number
of parameters.

-- 
-- Hubertus Franke  (frankeh@watson.ibm.com)
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