Re: [patch 1/2] add ALL_CPUS option to stop_machine_run()

[Rusty Russell <rusty@rustcorp.com.au>]

On Friday 29 February 2008 09:09:37 Max Krasnyanskiy wrote:
> Jason Baron wrote:
> > -allow stop_mahcine_run() to call a function on all cpus. Calling
> >  stop_machine_run() with a 'ALL_CPUS' invokes this new behavior.
> >  stop_machine_run() proceeds as normal until the calling cpu has
> >  invoked 'fn'. Then, we tell all the other cpus to call 'fn'.
>
> Jason, we're actually trying to reduce the usage of the stop_machine in
> general. It's a very big hammer that kills latencies and stuff. It'd be
> nice if we did not introduce any more dependencies on it. I guess in some
> case there is simply no other way to handle what need to do. But please
> think twice (or more :)).

Well, by definition modifying an immediate value should be very rare, so it's 
a reasonable candidate.

But stop_machine needs work.  It should not be as heavy as it is.

Cheers,
Rusty.