On Fri, Aug 22, 2014 at 06:18:03AM +0200, Juergen Gross wrote: > >>The resulting number of struct scsiif_request_segment is the sum of > >>seg[0..nr_segments-1].length / sizeof(struct scsiif_request_segment). > >> > > > >Where the nr_segments can only go Up to VSCSIIF_SG_TABLESIZE, so the max > >total SG entries you can is 13312 ( 4096 / 8 = 512 max per page, times > >26). > > In theory, yes. SG_ALL (being 128 today) is limiting this value.
Note that SG_ALL (or SCSI_MAX_SG_SEGMENTS which is a better name for it) is only the maximum if your driver doesn't support S/G chaining. Given that it and the Xen infrastructure seems to use the proper s/g list helpers it should support SCSI_MAX_SG_CHAIN_SEGMENTS easily. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
