svn commit: r194930 - in head: sbin/ipfw sys/netinet sys/netinet/ipfw

[Ben Kaduk]

On Wed, Jun 24, 2009 at 6:57 PM, Oleg Bulyzhin<oleg at freebsd.org> wrote:
> Author: oleg
> Date: Wed Jun 24 22:57:07 2009
> New Revision: 194930
> URL: http://svn.freebsd.org/changeset/base/194930
>
> Log:
>  - fix dummynet 'fast' mode for WF2Q case.
>  - fix printing of pipe profile data.
>  - introduce new pipe parameter: 'burst' - how much data can be sent through
>    pipe bypassing bandwidth limit.
>
> Modified:
>  head/sbin/ipfw/Makefile
>  head/sbin/ipfw/dummynet.c
>  head/sbin/ipfw/ipfw.8
>  head/sbin/ipfw/ipfw2.h
>  head/sys/netinet/ip_dummynet.h
>  head/sys/netinet/ipfw/ip_dummynet.c
>
[snip]
>
> Modified: head/sbin/ipfw/ipfw.8
> ==============================================================================
> --- head/sbin/ipfw/ipfw.8       Wed Jun 24 22:42:52 2009        (r194929)
> +++ head/sbin/ipfw/ipfw.8       Wed Jun 24 22:57:07 2009        (r194930)
> @@ -1,7 +1,7 @@
>  .\"
>  .\" $FreeBSD$
>  .\"
> -.Dd April 9, 2009
> +.Dd June 24, 2009
>  .Dt IPFW 8
>  .Os
>  .Sh NAME
> @@ -1943,6 +1943,20 @@ to reduce
>  the granularity to 1ms or less).
>  Default value is 0, meaning no delay.
>  .Pp
> +.It Cm burst Ar size
> +If the data rate exceeds the pipe bandwith limit
> +(and pipe was idle long enough),
> +.Ar size
> +bytes of data is allowed to bypass the
> +.Nm dummynet
> +scheduler (i.e. it will be sent without shaping), then transmission rate
> +will not exceed pipe bandwidth. Effective burst size calculated as follows:

There's a grammar error and a style error, here.  I'm actually not
entirely sure what
the intended meaning is, so it's a bit hard to fix the grammar error.
Looking at the code, it seems that in burst mode, extra data will be
allowed to be sent, though
it is capped to not exceed the pipe bandwidth.
Perhaps "... bytes of data is allowed to bypass the dummynet scheduler
(...), though
the transmission rate will still be capped so as to not exceed the
pipe's bandwidth."?

The style error is that the new sentence ("Effective burst size ...")
should start
on a new line.

I would also prefer to see the new sentence be an actual complete sentence
(i.e., "The effective burst size is calculated as follows"), though
there appears
to be at least one other bug of this form in the file already (see,
for example, the
quoted text at the beginning of this hunk: "Default value is no delay.", which
would benefit from a "the".)


Unrelated to this commit, there is a grammar error early in the file:

    312 Once
    313 .Fl p
    314 has been specified, any additional arguments as passed on to the preproc
essor
    315 for interpretation.

The 'as' in line 314 should be 'are'.
(This is from CVS r1.220, so the line numbers may not be current.)


Thanks,

Ben Kaduk


> +MAX(
> +.Ar size
> +,
> +.Nm bw
> +* pipe_idle_time).
> +.Pp
>  .It Cm profile Ar filename
>  A file specifying the additional overhead incurred in the transmission
>  of a packet on the link.
>