On Mon, 2006-12-11 at 15:50 +0100, Jens Axboe wrote: > > > > > Linux doesn't guarantee any request ordering for O_DIRECT io. > > > > > > > > so this means it can be inserted front and back. and no fixed > order? > > > > > > It'll be sort inserted like any other request. That might be > front, it > > > might be back, or it migth be somewhere in the middle. > > > > ic, so no special treatment here. > > Nope. In fact the block layer and io scheduler do not know that this > is > an O_DIRECT request, the bio originates from the same path as any > other > regular fs request.
one more question. since our point to have this block io is to by pass OS and send to high performance storage target. so if I use NOOP scheduler here, which simply add request to the tail of queue, then block io later will preserve the order. will this be ok? even device can do out of order, but device should do it in a safe way i think... - 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
