Re: pre-2.1.132-2..

MOLNAR Ingo (mingo@chiara.csoma.elte.hu)
Fri, 18 Dec 1998 16:07:20 +0100 (CET)


On Fri, 18 Dec 1998, Andrea Arcangeli wrote:

> This patch remove the unused bits. I don' t know what they are used for...
> Maybe for alignment, but without them the irq_desc_t struct is just 32*4
> bits so it seems just word aligned to me...

> struct hw_interrupt_type *handler; /* handle/enable/disable functions */
> struct irqaction *action; /* IRQ action list */
> unsigned int depth; /* Disable depth for nested irq disables */
> - unsigned int unused[2];

NO! :) On SMP, with shared data structures, we want to have 1 structure
per cacheline, otherwise we'd just play cacheline ping-pong for no good
reason.

on nonshared/UP data structures we want to have word alignment, correct.

(the padding is wrong in both cases btw, unless i cant count (damn, where
was that calculator). We need unused[5])

-- mingo

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