svn commit: r313854 - head/sys/cam/ctl

[Edward Tomasz Napierała]

On 0217T0522, Alexander Motin wrote:
> Author: mav
> Date: Fri Feb 17 05:22:58 2017
> New Revision: 313854
> URL: https://svnweb.freebsd.org/changeset/base/313854
> 
> Log:
>   Change the way MaxCmdSN is used.
>   
>   Before this change MaxCmdSN was reported as CmdSN + delta, that made it
>   limit number of requests in transmission from the initiator to target,
>   that was pretty useless.  After this change MaxCmdSN limits number of
>   requests queued to CTL, i.e. maximal queue depth for the initiator.
>   The default limit is 256 outstanding requests per initiator at a time.
>   
>   This code uses existing cs_outstanding_ctl_pdus counter to track queue
>   depth.  It's semantics doen't perfectly match, but close enough to not
>   add another counter.  Just don't set the maxtags below 2.

I like the change in principle, but I don't like the gratuitous change
of sysctl name.  It will break people's configs.  Could you rename it
back?  Thanks!