Justin T. Gibbs [gibbs@scsiguy.com] wrote:
> Comments have indicated since the 2.4.X days that Linux will never allocate
> segments that cross a 4GB boundary. If this is truely enforced, then this
> code can just be removed. It was only added out of paranoia (hence the
> printf) while adding high address support to the driver.
Jens can give the more complete answer on enforcement, and also correct
any mis-statements I made.
Base on the queue values below the aic7xxx driver should see the
following characteristics on IO. The IO should be for no more than 8k
made up of no more than 128 sg entries with no segment crossing the
seg_boundary_mask.
Adaptec AIC7xxx driver version: 6.2.33
scsi_alloc_queue: queue for aic7xxx
bounce_pfn: 0xfffff
bounce_gfp: 0x10 (GFP_NOIO)
queue_flags: 0x1 (QUEUE_FLAG_QUEUED)
max_sectors: 0x2000 (8192)
max_phys_segments: 0x80 (128)
max_hw_segments: 0x80 (128)
hardsect_size: 0x200 (512)
max_segment_size: 0x10000 (65536)
seg_boundary_mask: 0xffffffff
dma_alignment: 0x1ff (511)
-andmike
-- Michael Anderson andmike@us.ibm.com- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu May 15 2003 - 22:00:50 EST