RE: [PATCH] fix for-loop in sn_hwperf_geoid_to_cnode()

Luck, Tony
2006-03-03T21:52:56Z

>As an interim & admittedly "hackey" solution, we have introduced the
>notion of "cnodes". For cpu & memory nodes, the cnode number is
>the same as the nid (generic kernel node number). IO nodes are
>guaranteed to have numbers assigned after the last nid. IO nodes
>may have number >= 256.

Right now there are only three uses of for_each_node(). The two
in mm/slab.c only need to worry about nodes that have memory, so from
your description above, they won't be at all concerned about the I/O
only nodes that they will fail to scan.

Any ideas on the relative proportions of nodes with/without memory?
Should we consider renaming "for_each_node()" as "for_each_mnode()"
(meaning only scan nodes with memory). That would stop mm/slab.c
from allocating useless arraycaches for nodes with no memory. But
this is turning into a discussion that would have to happen on LKML.

Perhaps you could add an /*ACPI3.0-FIXME*/ comment (or some such)
to the loop in Dean's patch as a reminder to fix this later? That
might also serve as a clue to any janitor that tries to clean
up this code back to using "for_each_node()" (and a reminder to
me to not take such a patch).

-Tony