Re: [PATCH 3/11] powerpc: convert to generic helpers for IPI function calls

Jens Axboe
2008-04-22T12:13:31Z

On Tue, Apr 22 2008, Paul Mackerras wrote:
> Jens Axboe writes:
>
> > This converts ppc to use the new helpers for smp_call_function() and
> > friends, and adds support for smp_call_function_single().
>
> Looks OK, and runs on a dual G5 powermac here. I'll try on some
> bigger IBM boxes tomorrow, or maybe Anton can do that.

Thanks a lot, Paul!

> I notice that you have changed the semantics slightly in that
> previously, the powerpc implementation would wait for the other cpus
> to have taken the interrupt, and print a message if they didn't all
> take the interrupt (this was different from the function of the `wait'
> parameter, which said whether to wait for all cpus to finish executing
> the specified function).
>
> Now the generic smp_call_function_mask doesn't wait for the other cpus
> to take the interrupt. I don't think that's likely to be a problem,
> but I do think that's worth mentioning in the patch description.
>
> It's probably also worth mentioning that smp_send_stop no longer has
> the behaviour of doing its stuff even if someone is holding the lock,
> but that is OK (presumably) because now the lock (call_function_lock
> in the new code) is held for much shorter periods and there doesn't
> appear to be much danger of other cpus getting stuck or panicking
> while holding that lock.

I touched on both of these points in the initial mail, but perhaps you
missed it as I didn't CC everyone for the 0/11 part. I'll add the full
explanation to the 1/11 patch as well.

> You can put Acked-by: Paul Mackerras <paulus@samba.org> on the ppc
> patch, but please extend the description a bit as outlined above.

I'll add the ack, let me know if you still think I should do more on the
changelog side.

--
Jens Axboe