Re: I.1 - System calls - ioctl

Christoph Hellwig
2009-07-14T13:51:30Z

On Mon, Jul 13, 2009 at 12:53:13PM +0200, Peter Zijlstra wrote:
> On Mon, 2009-06-22 at 08:58 -0400, Christoph Hellwig wrote:
> > But talking about syscalls the sys_perf_counter_open prototype is
> > really ugly - it uses either the pid or cpu argument which is a pretty
> > clear indicator it should actually be two sys calls.
>
> Would something like the below be any better?
>
> It would allow us to later add something like PERF_TARGET_SOCKET and
> things like that.
>
> (utterly untested)

And makes the code a couple of magnitudes more ugly.. If you really
add a completely new targer adding a new system call wouldn't be a big
issue. Altough a socket seems like a pretty logical flag extension to
the cpu syscall (or sub-syscall currently), as it would still be
specified as trace the whole cpu socket for this given cpuid.