> From: Mark Hahn [mailto:hahn@xxxxxxxxxxx] > > > In its current implementation write-back mode acknowledges writes before > > they have reached non-volatile media. > > which is basically normal for unix, no? I am referring to when bi_end_io is called on the bio submitted to MD. Normally it is not called until after the bi_end_io event for the bio submitted to the backing disk. > > are you planning to support barriers? (which are the block system's way > of supporting filesystem atomicity). Not as a part of these performance experiments. But, I have wondered what the underlying issues are behind raid5 not supporting barriers. Currently in raid5.c:make_request: if (unlikely(bio_barrier(bi))) { bio_endio(bi, bi->bi_size, -EOPNOTSUPP); return 0; } -- Dan - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
