Messages in this thread | | | Date | Mon, 17 Jan 2005 18:50:57 +1100 | From | Paul Mackerras <> | Subject | Re: Horrible regression with -CURRENT from "Don't busy-lock-loop in preemptable spinlocks" patch |
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Chris Wedgwood writes:
> +#define rwlock_is_write_locked(x) ((x)->lock == 0)
AFAICS on i386 the lock word, although it goes to 0 when write-locked, can then go negative temporarily when another cpu tries to get a read or write lock. So I think this should be
((signed int)(x)->lock <= 0)
(or the equivalent using atomic_read).
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