I actually received 3+ off-post emails asking whether I was talking about initiator or target in the 100K IOPS case below and what did I mean by the ACKs. I was referring to the 'Initiator' side. ACKs == When scsi-ML down-calls the LLD via the queue-command, process the sgl's(if you like) and then trigger the scsi_done up-call path. Chetan Loke On Mon, Aug 23, 2010 at 12:07 PM, Chetan Loke <chetanloke@xxxxxxxxx> wrote: > On Mon, Aug 23, 2010 at 11:11 AM, Bart Van Assche <bvanassche@xxxxxxx> wrote: > >> >> There is an important design difference between SCST and LIO: SCST by >> defaults creates multiple threads to process the I/O operations for a >> storage target, while LIO only creates a single thread per storage target. >> This makes SCST perform measurably faster. >> > > Forget that. You could have discussed this if there were code reviews > or other mainline inclusion emails from James B. From what I have > heard, the decision was taken around 8-9 months back. > Would anyone like to either comment/validate/refute this please? If > not then I would kindly request these guys to stop taking us for a > test drive. And also I'm not sure when was the last time James B. > bench-marked our scsi-stack. Even if I ACK in the xmit-path then I > can't push more than 100K IOPs. But other folks have re-engineered our > linux-scsi stack and from what I've heard they can push > 300K+ IOPs. > So I would just ignore performance discussion because I don't think > folks have done even simple lame experiments in the last 1 year. Or > may be I'm completely wrong and so please enlighten me so that I can > re-run the tests. > > >> Bart. >> > Chetan Loke > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
