On Tue, Jun 03, 2014 at 07:14:44AM -0700, Christoph Hellwig wrote: > Honestly I think doing per-bdi writeback has been a major mistake. As > you said it only even matters when we have filesystems on multiple > partitions on a single device, and even then only in a simple setup, > as soon as we use LVM or btrfs this sort of sharing stops to happen > anyway. I don't even see much of a benefit except that we prevent > two flushing daemons to congest a single device for that special case > of multiple filesystems on partitions of the same device, and that could > be solved in other ways. To be fair, back when per-bdi writeback was introduced, having multiple partitions on a single disk was far more common, and the use of LVM was much less common. These days, many more systems using one big root filesystem, and or using flash where the parallel writes can actually be a good thing (since there isn't a single disk head which has to seek all over the HDD), the case for keeping per-bdi writeback is much weaker, if not non-existent. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
