> > For a dumb I/O card, you advertise SG_ALL capabilities, the IOMMU > > is going to merge things as it would have anyways, and you have > > code in the driver to advance SG entries after each "dumb I/O". > > Not that dumb ... they just have a limited number of SG slots. We > wouldn't want to run them as spoon fed PIO because that really would > kill performance. > > > There is zero value to the vmerge code, the real gains are being > > realized already. > > There is value to me in my testbed, which I can't achieve any other way > (except by buying different SCSI cards). > > As I said, you can compile it out on sparc just fine. I wish to keep it > running for parisc, so I'll maintain it. If it ever bit rots out of > parisc like it has done for the other architectures, then feel free to > remove it. > > James So try to #define BIO_VMERGE_BOUNDARY 0 for Pa-Risc and tell us what performance degradation do you see (and what driver do you use and what is the I/O pattern). If you show something specific, we can consider that --- but you haven't yet told us anything, except generic talk. Mikulas -- 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
