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

[Benjamin Kaduk]

On Thu, 25 Jun 2009, Oleg Bulyzhin wrote:

> On Wed, Jun 24, 2009 at 07:44:04PM -0400, Ben Kaduk wrote:
>
>> 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.
>
> It's no wonder - my english writing skill is poor.
>
>> 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."?
>
> Let me explain.  For example, we have pipe with bw 1Mbit/s and burst size is
> 5GByte. If we try to download 10Gbyte through this pipe following will happen:
> 1) 1st 5Gbyte of data will go with 'wire speed'.
> 2) last 5Gbyte will be shaped to 1Mbit/s
>
> Could you please mail me whole 'burst' part (as it should be), and i will fix
> it.

I think the following will suffice:

.It Cm burst Ar size
If the data to be sent exceeds the pipe's bandwidth limit
(and the pipe was previously idle), up to
.Ar size
bytes of data are allowed to bypass the
.Nm dummynet
scheduler, and will be sent as fast as the physical link allows.
Any additional data will be transmitted at the rate specified
by the
.Nm pipe
bandwidth.
The burst size depends on how long the pipe has been idle;
the effective burst size is calculated as follows:
MAX(
.Ar size
,
.Nm bw
* pipe_idle_time).
.Pp


The mdoc police may need to correct my markup.

>
>>
>> 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.)

I will submit a doc PR about the other issues.



Thanks for taking care of this!

-Ben Kaduk