Boost logo

Boost Interest :

Subject: Re: [Boost-cmake] ctest system information on mac
From: Julien Jomier (julien.jomier_at_[hidden])
Date: 2009-05-19 11:00:45

Bill Hoffman wrote:
>>>> Bill,
>>>> I am tearing apart the ParseSysCtl() method at the moment. CMake
>>>> does not have to Fork a process to get the sysctl values, you can call
>>>> them directly using sysctlbyname(..) method. I am currently doing this
>>>> for all the values. I have a few G4 boxes, a Core 2 Duo MacBook Pro
>>>> and a new Xeon to test with. I am going to try and find a G5 to get
>>>> some sysctl logs from so I can try an tell the difference between the
>>>> G4 boxes and the G5 boxes.
>>>> I just made any value having to do with memory a long long unsigned
>>> I don't see why. In GB we are not going to have long long worth of
>>> them,
>>> and it won't work on a 32 bit machine will it?
>> On my OS X 10.5.7 32 bit version I can ask for the total amount of ram
>> and get back a 64 bit number just fine. Same deal on my Xeon box at
>> work. As long as the pointer that is being passed to sysctlbyname is
>> the address to a 64 bit value it seems to work just fine. Of course I
>> am only thinking of OS X and forgetting about the rest of the world
>> ;-). I'll change the values back to longs and do the math to report
>> the memory results in GB which, as you mentioned, negates the need for
>> the long long variables.
>> Also what exactly is meant by the following:
>> GetLogicalProcessorsPerPhysical
>> GetNumberOfLogicalCPU
>> GetNumberOfPhysicalCPU
>> Could you tell me what the results of those would be for the following
>> conditions:
> I think it means this:
>> Quad Core, NON Hyperthreaded CPU.
> GetLogicalProcessorsPerPhysical = 1
> GetNumberOfLogicalCPU = 4
> GetNumberOfPhysicalCPU = 4
>> Quad Core, HyperThreaded CPU.
> GetLogicalProcessorsPerPhysical = 2
> GetNumberOfLogicalCPU = 8
> GetNumberOfPhysicalCPU = 4
>> On OS X I can get the 'number of packages" and cores_per_package, and
>> some other stuff but I am not sure those fit correctly into the values
>> from above.
> Take a guess...
> Julien, you did the original process information stuff, do you have
> anything to add to this?

Yes, that's exactly it. I think we need to modify the wording and change
CDash to report these numbers in a better way. Something like: 'total
number of cores' and 'total number of logical CPUs'. We don't really
need to display the ratio.

There is a bug report on the CDash bug tracker related to MacOS system
information. I'll see what I can do when we rework this part of CTest/CDash.


Boost-cmake list run by bdawes at, david.abrahams at, gregod at, cpdaniel at, john at