RE: [PATCH] nodemask.h: change any_online_node() to a staticinline

From: David Rientjes
Date: Wed Jan 06 2010 - 05:36:13 EST


On Tue, 5 Jan 2010, H Hartley Sweeten wrote:

> > Could you simply remove any_online_node() and replace its callers with
> > first_node(node_online_map) instead?
>
> No idea ;-)
>
> My main intention with this patch was to quite some sparse noise in
> net/sunrpc/svc.c. This seemed the cleanest way to do it.
>

It certainly silents the warning, which is good, but it also leaves behind
a macro that can simply be removed and reimplemented with
first_node(node_online_map) given the current use cases.

> It looks like any_online_node is, currently, only called by:
>
> arch/powerpc/mm/numa.c
> 3 places, twice setting a local int variable called 'nid' and once just
> returning the 'node' from the macro. All three call the marco as:
>
> ... any_online_node(NODE_MASK_ALL);
>

NODE_MASK_ALL is a nodemask_t with all bits set, so this will simply
return the first nid where node_online(nid) is true. That's equivalent to
first_node(node_online_map).

> net/sunrpc/svc.c
> 1 place, setting a local unsigned int variable called 'node'. Calls the
> macro as:
>
> ... any_online_node(node_online_map);
>

Same thing, except this doesn't require any iteration since node_online()
for the first bit in node_online_map will always be true.

> I really don't know if the macro could be replaced by first_node(node_online_map).
>

It can, so I think an even better step would be to remove
any_online_node() completely and convert the callers you've identified to
use the new implementation.

Thanks!
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