On Sun, Sep 13, 2015 at 4:12 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > Really need to run these numbers on slower disks where block layer > merging makes a difference to performance. Yeah. We've seen plugging and io schedulers not make much difference for high-performance flash (although I think the people who argued that noop should generally be used for non-rotating media were wrong, I think - the elevator ends up still being critical to merging, and while merging isn't a life-or-death situation, it tends to still help). For rotating rust with nasty seek times, the plugging is likely to make the biggest difference. Linus -- 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