[Stgt-devel] ibmvio is slow

[Bastian Blank]

On Tue, Aug 14, 2007 at 08:36:02PM +0200, Bastian Blank wrote:
> There is only lvm between it. This looks like some sort of read-ahead
> for the data, which should not happen for write requests. I tried to dig
> a little bit in the block code but was not able to found the cause.

I found something:

scsi_host_get_command
| int write = (data_dir == DMA_TO_DEVICE);

According to ibmvstgt, this is a write to the scsi device, aka data
transfer to this system.

| rq = blk_get_request(shost->uspace_req_q, !write, gfp_mask);

The second parameter should be READ or WRITE, not true/false and it
seems to have the wrong direction.

Bastian

-- 
War is never imperative.
		-- McCoy, "Balance of Terror", stardate 1709.2