On Tue, 2013-08-20 at 20:00 +0200, Bart Van Assche wrote: > On 08/20/13 19:04, Nicholas A. Bellinger wrote: > > On Tue, 2013-08-20 at 18:15 +0200, Bart Van Assche wrote: > >> On 08/20/13 18:11, Nicholas A. Bellinger wrote: > >>> On Tue, 2013-08-20 at 14:05 +0200, Bart Van Assche wrote: > >>>> This patch series consists of four patches that address device removal > >>>> issues and three patches that improve performance of the SCSI mid-layer. > >>> > >>> Perhaps it would be useful to know what the performance improvement > >>> actually is..? Eg: fio numbers before and after. > >> > >> The optimizations in this patch series are micro-optimizations. Their > >> performance impact is small but measurable. Peak IOPS results are > >> improved by about 1% by each of these performance improvements for a > >> low-latency transport. > > > > So that is 250K to 252.5K per LUN, or what..? > > The exact numbers depend on the number of CPU's in the initiator system, > the number of CPU's in the target system, the transport type, HCA model, > SCSI target stack configuration, target storage medium etc. If you want > to verify yourself the impact of this patch without all these > dependencies, that's possible by running a test against the scsi_debug > driver. > <yawn>, I only care about the performance against upstream code, so that would mean scsi_debug here. Typically the onus of demonstrating a performance improvement is on the patch submitter (eg: not the reviewer). But it would be at least useful to know the actual benefit with results as an incremental step, short of avoiding this code entirely for scsi-mq. --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
