svn commit: r317143 - in head/sys/cam: . ata scsi

[Slawa Olhovchenkov]

On Wed, Apr 19, 2017 at 03:04:53PM +0000, Scott Long wrote:

> Author: scottl
> Date: Wed Apr 19 15:04:52 2017
> New Revision: 317143
> URL: https://svnweb.freebsd.org/changeset/base/317143
> 
> Log:
>   Add infrastructure to the ATA and SCSI transports that supports
>   using a driver-supplied sbuf for printing device discovery
>   announcements. This helps ensure that messages to the console
>   will be properly serialized (through sbuf_putbuf) and not be
>   truncated and interleaved with other messages. The
>   infrastructure mirrors the existing xpt_announce_periph()
>   entry point and is opt-in for now. No content or formatting
>   changes are visible to the operator other than the new coherency.
>   
>   While here, eliminate the stack usage of the temporary
>   announcement buffer in some of the drivers. It's moved to the
>   softc for now, but future work will eliminate it entirely by
>   making the code flow more linear. Future work will also address
>   locking so that the sbufs can be dynamically sized.
>   
>   The scsi_da, scs_cd, scsi_ses, and ata_da drivers are converted
>   at this point, other drivers can be converted at a later date.
>   A tunable+sysctl, kern.cam.announce_nosbuf, exists for testing
>   purposes but will be removed later.
>   
>   TODO:
>   Eliminate all of the code duplication and temporary buffers.  The
>   old printf-based methods will be retired, and xpt_announce_periph()
>   will just be a wrapper that uses a dynamically sized sbuf.  This
>   requires that the register and deregister paths be made malloc-safe,
>   which they aren't currently.

Thanks!
MFC planed?