Hannes Reinecke wrote: > Hannes Reinecke wrote: >> Hi Mike, >> >> finally I've managed to track down the lost TTT issue. >> >> We're continuing to get responses from the target >> even after we have send the TMF PDU (no surprise there). >> However, the target considers all R2Ts send _before_ >> the tmf response is sent as valid, requiring us >> to finish off the R2T sequence by sending a Data-Out >> PDU even _after_ we have received the TMF response. >> >> So I've implemented a (rather hackish) 'flush data out' >> function, which flushes all outstanding Data out >> PDUs for a given LUN. Using this things are much >> better to the point that the 'dropped R2T' messages >> disappeared. >> > Well, I've been to fast. I'm having a rather unfavourable > (non-)interaction between the xmit thread and the recv > side; as the recv side runs effectively asynchronous > to the xmit thread there is a change that wealready > received the R2T PDU but haven't had a chance to > process it as it's waiting on the session spinlock. > Maybe it's an idea to have a per-task spinlock to > ease the lock contention on the per-session spinlock. > And, incidentally, what is the reason for first setting the SUSPEND bit in iscsi_suspend_tx and _then_ flush the workqueue? Surely this will just empty the workqueue without any real work done here (as the xmit thread will be short-circuited anyway). As we have to flush in the sense of actually _transmitting_ outstanding requests this looks (and, in fact, proves) to be rather detrimental here.
Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to firstname.lastname@example.org To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~----------~----~----~----~------~----~------~--~---