On Wed, 21 Nov 2018, Christoph Hellwig wrote: > Hi all, > > you in the To list maintain or wrote SCSI drivers that set the > DISABLE_CLUSTERING flag, which basically disable merges of any > bio segments. We already have the actual max_segment size limit > to say which length a segment should have, independent of merged > or originally created, so this limit generally should rarely if > ever be required, and mostly is an old cut an paste error. > Are you referring to blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); in drivers/scsi/scsi_lib.c? Is the segment size limitation of the DMA controller the only reason to want DISABLE_CLUSTERING? > Can you go over your drivers and check if it could be removed? > Adding Sun 3 maintainer to Cc. Besides sun3_scsi.c and atari_scsi.c, the SCSI drivers I take an interest in don't actually use a DMA controller. If my question about DMA controllers gets a "yes" then I guess I can send a patch for those drivers. --
