Re: [Boost-build] test timing information

From: K. Noel Belcourt (kbelco_at_[hidden])
Date: 2007-11-10 14:30:25

On Nov 10, 2007, at 11:52 AM, Vladimir Prus wrote:

> David Abrahams wrote:
>
>>
>> Did we ever put code in bjam that will allow us to get timing
>> information for individual build steps?
>
> I think you tried to do that, but I'm not sure it was ever finished.
>
>> I realize we are getting
>> timestamps, but that doesn't quite amount to the same thing,
>> especially because we get a stamp for the beginning of a test run but
>> not the end, but also because we really want to know the user and/or
>> system time rather than real time, which can be grossly distorted by
>> other activity on the machine.
>
> The user and/or system time can be likewise distorted by other  
> activity -- in
> particular the number of cache faults is dependent on what other  
> application
> are busy thrashing the cache.

We could add the ability to time all child processes to bjam, since  
that would give us the most reliable numbers (using a call to  
getrusage when the child process terminates).  It might take a bit of  
effort but I'd be willing to do it (it would have significant value  
to our organization as well).  We'd need to get Rene's help to (1)  
decide if it could be handled efficiently in Windows (2) whether /  
when he might have the time to do it.

--  Noel