On Thu, Mar 08, 2012 at 08:02:07PM -0500, Chris Mason wrote: > > Right before submission to the bio layer? Or right before the device > > driver sends the request to the host bus adapter? I was thinking of > > the latter.... > > blktrace can probably give us numbers for how big that wait is, but > hopefully it is very small. If it is too big, you can always bump > nr_requests. Not necessarily; things can get stalled for quite a while due to ionice or io rate throttling. There's quite a lot that can happen after submit_bio, at the cfq layer, for example. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html