Re: [PATCH] rt-tests: incorrect first latency value for --verbose option

[Frank Rowand <frank.rowand@am.sony.com>]

On 05/07/12 14:41, John Kacur wrote:
> 
> 
> On Wed, 2 May 2012, Frank Rowand wrote:
> 
>>
>> When the --verbose option is selected, the first value for each thread is
>> incorrectly reported as zero.
>>
>> This is because when collecting the first value, the index into stat->values is
>> incremented from zero to one before storing the value.  But when printing the
>> values, the first value printed is stat->values[0], which has been initialized
>> to zero.
> 
> Hi Frank
> 
> Ok, no more posting from me after winning a bottle of whiskey at the Irish 
> Pub on quiz night. :)

Or if you do, you should share a bit of the whiskey with me.

> 
> I've been looking at this one, and I'm not sure about it.
> According to the help output, 
> 
> "-v       --verbose         output values on stdout for statistics
>                            format: n:c:v n=tasknum c=count v=value in us"
> 
> ./cyclictest --verbose -p99 -t | awk '$2~/^0/{ print }' 
> 
>        0:       0:       0
>        1:       0:       0
>        2:       0:       0
>        3:       0:       0
>        4:       0:       0
>        5:       0:       0
>        6:       0:       0
>        7:       0:       0
> 
> So, it looks like the values are 0 at count 0, doesn't that make sense?

Nope.  The event for count == 0 is the first event.  And the first event
has an actual latency that is not zero on the system I tested it on.

-Frank