On Thu, 2014-02-06 at 18:10 +0100, Bart Van Assche wrote: > On 02/06/14 17:56, James Bottomley wrote: > > Could you benchmark this lot and show what the actual improvement is > > just for this series, if any? > > I see a performance improvement of 12% with the SRP protocol for the > SCSI core optimizations alone (I am still busy measuring the impact of > the blk-mq conversion but I can already see that it is really > significant). Please note that the performance impact depends a lot on > the workload (number of LUNs per SCSI host e.g.) so maybe the workload I > chose is not doing justice to Christoph's work. And it's also important > to mention that with the workload I ran I was saturating the target > system CPU (a quad core Intel i5). In other words, results might be > better with a more powerful target system. > Starting with a baseline using scsi_debug that NOPs REQ_TYPE_FS commands to measure improvements would be a better baseline vs. scsi_request_fn() existing code that what your doing above. That way at least it's easier to measure specific scsi-core overhead down to the LLD's queuecommand without everything else in the way. --nab -- 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
