RE: Synchronizing Bit operations V2

From: Chen, Kenneth W
Date: Thu Mar 30 2006 - 20:26:22 EST


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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/