Messages in this thread | | | Date | Wed, 23 Apr 2008 10:11:48 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH 11/11] s390: convert to generic helpers for IPI function calls |
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On Wed, Apr 23 2008, Heiko Carstens wrote: > On Tue, Apr 22, 2008 at 08:50:27PM +0200, Jens Axboe wrote: > > This converts s390 to use the new helpers for smp_call_function() and > > friends, and adds support for smp_call_function_single(). Not tested, > > but it compiles. > > > > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > > Cc: Heiko Carstens <heiko.carstens@de.ibm.com> > > Signed-off-by: Jens Axboe <jens.axboe@oracle.com> > > Your generic patch changes semantics of smp_call_function(). At least the > s390 version of smp_call_function() mask used to not return unless all IPIs > where received on the target cpus. > Your patch changes that. It will already return as soon as all IPIs have > been sent. Unfortunately Martin's etr code in arch/s390/kernel/time.c
Yep, this is what I mentioned in the intro mail.
> relies on exactly the old semantics.
OK, I could not see anything which relied on that and I did think that it was a somewhat odd interface. By the time that smp_call_function() stops waiting for startups, we could easily be in the condition that the N-1 CPUs executed the function part a long time ago. I just didn't see much usefulness in that, you may as well just set wait == 1 in that case.
> Since this seems to be an s390 only issue, could you just drop the s390 > conversion patch? We'll have to think about how to change the err code > and convert later I guess.
I'll drop the s390 bits. I can easily add something like smp_call_function_foo() that has this behaviour.
-- Jens Axboe
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