On Wed, Apr 11 2007, Ming Zhang wrote: > Hi All > > For this ISSUE event, currently it is in elv_next_request(), any idea > why it is not in elv_dequeue_request() which is where the request marked > as on-the-fly and send to lower level?
elv_next_request() is the driver hand-off point, so should be pretty close to the issue time unless the request gets requeued due to some busy condition (which will also be logged). elv_dequeue_request() may happen much later, some drivers do it right before calling the io completion handler - IDE does this - since it leaves the request on the queue list for the duration of the operation. So moving the ISSUE event to elv_dequeue_request() would not be correct. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
