Re: merging discard request in the block layer

[Christoph Hellwig]

On Tue, Mar 22, 2011 at 10:03:57PM +0100, Jens Axboe wrote:
> > That would seem to indicate a bug in the merging logic instead.
> 
> What kind of max discard size does you device have? If the max discard
> size is smaller than the regular request size, this could help.

It's a SCSI device, so the max discard size is a lot larger:

# cat /sys/block/sda/queue/max_sectors_kb
512
# cat /sys/block/sda/queue/max_hw_sectors_kb 
32767
# cat /sys/block/sda/queue/discard_max_bytes 
4294966784

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/