[cfarm-users] Nice on GCC202?

[Jeff Law]

On 03/09/2018 10:14 AM, Jason Merrill wrote:
> On Fri, Mar 9, 2018 at 12:00 PM, Jeff Law via cfarm-users
> <cfarm-users at lists.tetaneutral.net> wrote:
>> On 03/09/2018 01:54 AM, Anatoly Pugachev via cfarm-users wrote:
>>> On Fri, Mar 9, 2018 at 11:04 AM, Baptiste Jonglez via cfarm-users
>>> <cfarm-users at lists.tetaneutral.net> wrote:
>>>> On 08-03-18, Jeffrey Walton wrote:
>>>>> On Thu, Mar 8, 2018 at 6:19 PM, Baptiste Jonglez
>>>>> <baptiste at bitsofnetworks.org> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On 08-03-18, Jeffrey Walton via cfarm-users wrote:
>>>>>>> Hi Everyone,
>>>>>>>
>>>>>>> GCC202 is a Sparc64 machine. It has 16 cpus and each cpu has 16 cores
>>>>>>> for a total of 256 virtual cpu's.
>>>>>>
>>>>>> Where did you see those 256 "virtual cpu's"?  According to htop,
>>>>>> /proc/cpuinfo and https://cfarm.tetaneutral.net/machines/list/ it only has
>>>>>> 16 "threads".
>>>>>
>>>>> /sys/devices/system/cpu
>>>>>
>>>>> Related, do you know where the CPU freq is tucked away on Sparc64? It
>>>>> is not in the places I usually look, like /proc/cpuinfo and
>>>>> /sys/devices/system/cpu.
>>>>
>>>> To kill two birds with one stone:
>>>>
>>>> $ cat /sys/devices/system/cpu/cpu*/clock_tick | uniq -c
>>>>      16 3599910000
>>>>
>>>> So, only 16 threads, each at 3.6 GHz.
>>>
>>> Just to clarify things, gcc202 is LDOM [1] (read virtual machine),
>>> running on a SPARC T5-2 server [2], which has 2x CPU sparc T5 [3].
>>> gcc202 is allocated only 2 cores (out of 32 cores (2 cpus) in physical
>>> server), so it's 16 threads in total:
>>>
>>> sysadmin at deimos:~$ ldm list cfgcc
>>> NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  NORM  UPTIME
>>> cfgcc            active     -n----  5003    16    8G       6.5%  6.5%  9d 20h 6m
>>>
>>> I could probably add 1 more core (8 more threads), if someone really
>>> needs it and/or building big projects which will actually use more
>>> threads.
>>>
>>> And ping me, if it will need more RAM, still have some available.
>>>
>>> So, if you run parallel make, please consider to use 3/4 of total
>>> threads (depends on a time your project building, if it will complete
>>> in a short amount of time, use 3/4 of total threads, if it runs longer
>>> take just a half of available threads).
>> Thanks for the guidance.  I've throttled my builder appropriately for
>> gcc202.
> 
> I tend to use both -j and -l to avoid overloading.
Yup.  I use 'em both in a manner similar to what you do -- I've just
added an override as nproc --all is a bit over-optimistic on gcc202 :-)

jeff