On Mon, Jul 15, 2013 at 01:41:05PM -0400, Prarit Bhargava wrote:
On 07/15/2013 01:33 PM, "Jóhann B. Guðmundsson" wrote:
> On 07/15/2013 05:21 PM, Prarit Bhargava wrote:
>> I've done some testing across various systems (both "large" and
>> Increasing NR_CPUS seems to have a negligible effect. I see about a 1.1M
>> increase in memory usage when switching between 128 cpus and 5120 cpus. Since
>> most systems ship with 4G or more these days, I cannot see an issue with
>> consuming a small amount of memory like this.
>> The current NR_CPUS in Fedora is 128 and the current NR_CPUS in RHEL7 is 5120.
>> I do not see any reason that those values have to be different anymore.
> I guess the question here is anyone aware of anyone running Fedora with 128
Yes - me. And I have HW that exceeds that number.
> cpu's or for that matter 5120.
Yes -- Russ, care to share some numbers?
We have a 5120 cpu system: 128 blades, 2 sockets per blade, 10 cores per socket,
2 HyperThreads per core. That system has 8 TB memory.
We have another with 4096 cpus: 128 blades, 2 sockets per blade, 8 cores per
socket, 2 HyperThreads per core. That system has 16 TB memory.
Many smaller ones in the 512-1024 cpu range.
FWIW, RHEL6 is CONFIG_NR_CPUS=4096
Russ Anderson, OS RAS/Partitioning Project Lead
SGI - Silicon Graphics Inc rja(a)sgi.com