RE: Synchronizing Bit operations V2

From: Chen, Kenneth W <>
Date: 2006-03-31 12:29:56
Christoph Lameter wrote on Thursday, March 30, 2006 5:13 PM
> Then there will no barrier since clear_bit only has acquire semantics.
> This is a  bug in bit operations since smb_mb__before_clear_bit does
> not work as documentted.

Well, please make up your mind with:

Option (1):

#define clear_bit                     clear_bit_mode(..., RELEASE)
#define Smp_mb__before_clear_bit      do { } while (0)
#define Smp_mb__after_clear_bit       smp_mb()

Or option (2):

#define clear_bit                     clear_bit_mode(..., ACQUIRE)
#define Smp_mb__before_clear_bit      smp_mb()
#define Smp_mb__after_clear_bit       do { } while (0)

I'm fine with either one.

- Ken
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Received on Fri Mar 31 12:29:47 2006

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