On Sat, 2008-07-19 at 21:07 -0700, David Miller wrote: > From: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Date: Sat, 19 Jul 2008 21:17:08 -0500 > > > Try this patch > > I'd rather remove the vmerge code, it doesn't buy us > anything, and for something so complex and so hard to > keep working correctly it's existence is far from > justified these days. You can ... as soon as BIO_VMERGE_BOUNDARY is undefined or set to zero, it gets compiled out of the block code. Since we're using it successfully in parisc, I don't want the block code removed, but I don't see a reason to force other architectures to use it. However, it has two use cases. One is the legacy one of making rather dumb I/O cards perform better (which is the primary on on parisc), but there is a current one making huge transfers go through SCSI using using the sg_table code. That latter is pretty vital to me since I have to keep the code working, but I don't really have any SCSI cards that can take advantage of it without virtual merging. As a slight irony, IBM is trying to persuade me that a ppc would be better than a parisc for big endian I/O testing ... so I might just be seeing if I can make virtual merging work on power too. James -- 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
