Hey, On Fri, Feb 21, 2014 at 06:46:24PM -0500, Peter Hurley wrote: > It's a long story but the short version is that > Documentation/memory-barriers.txt recently was overhauled to reflect > what cpus actually do and what the different archs actually > deliver. > > Turns out that unlock + lock is not guaranteed by all archs to be > a full barrier. Thus the smb_mb__after_unlock_lock(). > > This is now all spelled out in memory-barriers.txt under the > sub-heading "IMPLICIT KERNEL MEMORY BARRIERS". So, that one is for unlock/lock sequence, not smp_mb__after_unlock(). Urgh... kinda dislike adding smp_rmb() there as it's one of the barriers which translate to something weighty on most, if not all, archs. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
