[cfarm-users] Nice on GCC202?

[Jeff Law]

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.

jeff