Re: [patch] waitqueue optimization, 2.4.0-test7

Date: Mon Aug 28 2000 - 12:45:26 EST

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.

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to Please read the FAQ at

This archive was generated by hypermail 2b29 : Thu Aug 31 2000 - 21:00:22 EST