Profiling: 0 entries but high costs

[Simon Marlow]

On 05/10/2010 16:54, Stefan Wehr wrote:
> here is some profiling output which shows strange behavior:
>
> COST CENTRE                          MODULE
>                     no.     entries  %time %alloc  %time %alloc
>
> MAIN                                 MAIN
>                         1         0    0.0    0.0  100.0  100.0
>   ...
>   CAF:runHttpNewsWatch_watchNews
> MobileGateway.DataClient.HttpNewsWatch                8685         1
>   0.0    0.0   90.2   95.7
>    watchNews                          MobileGateway.LubSync.NewsWatch
>                     12239        14    0.0    0.0   90.2   95.7
>     watchNewsIteration                MobileGateway.LubSync.NewsWatch
>                     12283         4    0.0    0.0   90.2   95.7
>      ...
>      getAndProcessNews                MobileGateway.LubSync.NewsWatch
>                     12284       156    0.0    0.0   90.2   95.7
>       ...
>       handleNewsItem                  MobileGateway.LubSync.NewsWatch
>                     12526       577    0.0    0.0   88.9   95.1
>        ...
>        dsLoadObject_a7eq              MobileGateway.DataClient.HttpDs
>                     12648       144    0.0    0.0   84.0   91.5
>         loadObject                    MobileGateway.DataClient.HttpDs
>                     12650       720    0.7    0.6   84.0   91.5
>          ...
>          runNewsWatchTInIO
> MobileGateway.DataClient.HttpNewsWatch               12654         0
>   0.0    0.0   69.5   80.3
>           runHttpDsM                  MobileGateway.DataClient.HttpDs
>                     12655         0   69.5   80.3   69.5   80.3
>
>
> The cost centre runHttpDsM has yero entries but rather high costs. How
> can this be? According to the manual, the entries column specifies
> "the number of times this particular point in the call graph was
> entered". From this definition I would conclude that a cost centre
> with zero entries cannot have any costs. What am I doing wrong?

It certainly looks like a bug.  Please report it, giving a test case to 
reproduce it if you can.  I can't guarantee we'll fix it in the near 
term, as the profiling system has a number of problems in this area and 
is in need of a thorough overhaul (starting with figuring out how it is 
supposed to work!).

Cheers,
	Simon