Subject: Re: NCR Driver Problems
To: None <current-users@NetBSD.ORG>
From: Christoph Badura <>
List: current-users
Date: 01/30/1996 21:31:18
Charles Hannum writes:

> That's not entirely true.  At least for file systems, the driver gets
> a pointer to a buf, which will have B_ASYNC turned off for a           
> synchronous write.  I don't offhand see a reason why a driver couldn't
> use this for ordering.

Because that doesn't give a hint what the ordering relation ship
between the buffers is.

The best you could do is give all such requests a SCSI ordered queue

However, the synchronous writes from two processes causing metadata
updates on different files are likely to be independent and don't need
ordering.  So you would lose concurrency.

Not that it matters with the i386-NCR driver.  That one uses ordered
queue tags on all requests except reads.  I dunno if it's worth
changing, though.

Christoph Badura

You don't need to quote my .signature.  Everyone has seen it by now.
Besides, it doesn't add anything to the current thread.