[cfarm-users] Nice on GCC202?

[Jason Merrill]

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.

if procs=$( getconf _NPROCESSORS_ONLN 2>/dev/null ||
        (type lscfg >/dev/null 2>&1 && lscfg | grep proc | wc -l) ||
        (type psrinfo >/dev/null 2>&1 && psrinfo | wc -l) ); then
  export MAKEFLAGS="-j $procs -l $procs"
fi