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DateMon, 28 Aug 2000 11:45:26 -0600
From yodaiken@fsmlabs ...
SubjectRe: [patch] waitqueue optimization, 2.4.0-test7
On Mon, Aug 28, 2000 at 07:51:55PM +0200, Ingo Molnar wrote:
> we have a number of other places that rely on clear_bit() being atomic -
> if this isnt true anymore on Alpha then we could make it nonatomic on x86

So what is the semantics of a non-atomic clear-bit?

BTW: here is the comment in include/asm-i386/bitops.h -- similar in
the other architectures I looked at.

* These have to be done with inline assembly: that way the bit-setting
* is guaranteed to be atomic. All bit operations return 0 if the bit
* was cleared before the operation and != 0 if it was not.




--
---------------------------------------------------------
Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com
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