On 29/06/17 03:35 PM, Allen Hubbe wrote: >> It is not a workaround for alignment restrictions of the mws. It is a restriction to avoid the use of >> doorbells and scratchpads. Memory windows are used exclusively. >> >> Read msi-x local <addr,data> and send that to the peer: > > https://github.com/ntrdma/ntrdma/blob/master/drivers/ntc/ntc_ntb_msi.c#L583 > >> Transform peer's addr to the memory window region: > > https://github.com/ntrdma/ntrdma/blob/master/drivers/ntc/ntc_ntb_msi.c#L603 > >> Append a dma immediate value operation after other operations, to write the data at addr: > > https://github.com/ntrdma/ntrdma/blob/master/drivers/ntc/ntc_ntb_msi.c#L1195 Ok, I'm a little bit confused at the links you are pointing me to. The patch you nak'd only makes changes to ntb_mw_get_align and ntb_mw_count: 1) ntb_mw_get_align gets the last two parameters of what was formerly ntb_mw_get_range. However, the only two uses of get_range I can find in the ntrdma code set those two parameters to NULL and thus would not use ntb_mw_get_align. 2) ntb_mw_count is technically a new function (ntb_peer_mw_count is equivalent to the old function of that name). However, the one place in ntrdma where it would be called is during de-initialization. So if the link goes down before deinit, the client will not correctly clean up all the memory windows. So, it seems to me that ntb_mw_get_align is fine the way I have it but we should probably change ntb_mw_count: I'll get rid of the check for link in that function and then have the switchtec driver locally cache the peer's memory windows whenever the link goes up. So if the link is down it will return the number of mws the last time the link was seen. (And if the link was never seen it will return 0). Thoughts? Logan
