Re: [patch]workqueue: copy attr with all fields.

[Shaohua Li <shli@kernel.org>]

On Tue, Jul 30, 2013 at 10:14:19AM -0400, Tejun Heo wrote:
> Hello, Shaohua.
> 
> On Tue, Jul 30, 2013 at 01:49:55PM +0800, Shaohua Li wrote:
> > > Note that copy_workqueue_attrs() is also used while creating worker
> > > pools and this change would mean that there will be worker pools with
> > > no_numa attribute assigned basically randomly depending on which wq
> > > created the pool for the first time which should be fine AFAICS but
> > > isn't very nice.  Given that there's only single place where a pool's
> > > attrs is set, maybe it'd be best to clear no_numa right after copy and
> > > explain what's going on there?
> > 
> > alloc_workqueue_attrs() always zero the new allocated attr.
> 
> Hmmm?  Yeah, sure, that's how it currently is always zero for all
> pools.  If you change the copy function, it'll now be set to whatever
> the input value was when a pool was created, which shouldn't break
> anything but is a bit confusing as no_numa doesn't have anything to do
> with pools directly.  Just in case, I'm talking about
> copy_workqueue_attrs() call in get_unbound_pool().

Hmm, I didn't agree it's more confusing to change copy_workqueue_attrs(), the
name of the function suggests it is a 'copy'. And clearing no_numa in
apply_workqueue_attrs() after copy_workqueue_attrs() looks like a hack to me.
But it depends on you, feel free to fix it by yourself.

Thanks,
Shaohua