Cc: Alan Mayer <ajm@...>, <mingo@...>, linux-kernel list <linux-kernel@...>, Robin Holt <holt@...>, Jack Steiner <steiner@...>, Russ Anderson <rja@...>
I do agree that it's ugly, but I think the ugliness is more serious than
that.
What I think we should do is to make NR_IRQS no longer be a compile-time
constant, but instead just do something like
unsigned int NR_IRQS __read_mostly;
and then just set it early in the boot sequence depending on the real CPU
numbers etc.
I realize that this will require some changes to a few arrays that are
statically allocated and depend on NR_IRQ's (notably "irq_desc"), but
don't you guys think that this would be a cleaner thing?
[ I suspect that irq_desc[] itself could quite reasonably be a rather much
smaller __read_mostly hash-table of dynamically allocated entries - the
thing would be only modified at boot, so it should cache beautifully
even across hundreds of CPU's ]
Whatever. I'm not opposed to this whole static thing, but I do wonder if
it's worth doing that way. There *may* be performance reasons for doing it
the way we're doing it, but quite frankly, I think the #define is mostly
purely historical, from when it was just a fixed number (originally 16!)
and it made sense to think of it as a small static array.
Linus
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