On Mon, Aug 23, 2010 at 02:03:26PM -0400, Chetan Loke wrote: > 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. > Uhm, Intel and Microsoft demonstrated over 1 million IOPS using software iSCSI and a single 10 Gbit Ethernet NIC (Intel 82599). How come there is such a huge difference? What are we lacking in Linux? -- Pasi > 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 > > > > ------------------------------------------------------------------------------ > Sell apps to millions through the Intel(R) Atom(Tm) Developer Program > Be part of this innovative community and reach millions of netbook users > worldwide. Take advantage of special opportunities to increase revenue and > speed time-to-market. Join now, and jumpstart your future. > http://p.sf.net/sfu/intel-atom-d2d > _______________________________________________ > Scst-devel mailing list > Scst-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/scst-devel -- 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
