Davidlohr Bueso <[email protected]> writes: > This is really about simplifying the double xchg patterns into > a single cmpxchg, with the same logic. Other than the immediate > cleanup, there are some subtleties this change deals with: > > (i) While the load of the old bt is fully ordered wrt everything, > ie: > > old_bt = xchg(&q->blk_trace, bt); [barrier] > if (old_bt) > (void) xchg(&q->blk_trace, old_bt); [barrier] > > blk_trace could still be changed between the xchg and the old_bt > load. Note that this description is merely theoretical and afaict > very small, but doing everything in a single context with cmpxchg > closes this potential race. > > (ii) Ordering guarantees are obviously kept with cmpxchg.
Hi David, The patch itself looks ok, but it doesn't seem to apply to a recent kernel tree. It appears as though it is white-space damaged. Would you mind re-sending it? Thanks! Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
