Re: SCSI RAM driver

[FUJITA Tomonori <tomof@acm.org>]

On Tue, 19 Feb 2008 06:31:20 -0700
Matthew Wilcox <matthew@wil.cx> wrote:

> On Tue, Feb 19, 2008 at 10:14:53PM +0900, FUJITA Tomonori wrote:
> > I see that two drivers have very different objectives but if we add
> > use_thread option to scsi_debug (we can do easily), it seems that
> > scsi_debug can provide all the features that scsi_ram does.
> 
> It's not just use_thread.  It's also discard_read/discard_write.

scsi_debug has a similar option, fake_rw, which discards both read and
write data.


> And scsi_ram has a different data storage model from scsi_debug --
> scsi_debug simulates an arbitrarily sized disc by wrapping around some
> small (virtually) contiguous allocation of pages; scsi_ram actually
> allocates the amount of ram that it's told to.  This can be solved with
> another module parameter, of course.

IIRC, if virtual_gb option is set to zero, scsi_debug allocates the
amount of ram that it's told to.


> I'm in no way opposed to merging the two; it's a question of whether
> Doug will mind me doing some surgery on his driver.