Clear Linux Will Now Handle Up To 512 CPU Cores / vCPUs

[phoronix]

Phoronix: Clear Linux Will Now Handle Up To 512 CPU Cores / vCPUs

Following yesterday's article looking at the performance of Intel's Clear Linux running on AMD EPYC 4th Gen "Genoa" with great performance results even though Clear's kernel was limited to 320 of the 384 available logical CPU cores for the EPYC 9654 2P setup, the kernel has now been adjusted to handle up to 512 CPUs...

https://www.phoronix.com/news/Clear-Linux-512-NR_CPUS

[linuxgeex]

Wow we're about 2 generations away from hitting 1990's IRIX cpu core counts (1024+) on Linux.

[coder]

Doesn't Intel support up to 8-CPU configurations? Is that a thing, any more? The last CPU I can find that has 8-socket scalability is this 24-core model from 5 years ago:

https://ark.intel.com/content/www/us...-2-40-ghz.html

Still, that should enable 384 threads. So, I'm a little surprised this limit hadn't been raised already.

[coder]

Wow we're about 2 generations away from hitting 1990's IRIX cpu core counts (1024+) on Linux.

Based on the article, it sounds like Clear Linux just had it set low, for performance reasons. The article goes on to say:

"... still below the top-end lofty limit of of 8192 NR_CPUS set by some Linux distribution vendor kernel builds."

So, it sounds like Linux already passed IRIX, a while ago.

[arjan_intel]

Based on the article, it sounds like Clear Linux just had it set low, for performance reasons. The article goes on to say:

"... still below the top-end lofty limit of of 8192 NR_CPUS set by some Linux distribution vendor kernel builds."

So, it sounds like Linux already passed IRIX, a while ago.

setting the variable high, and actually booting and working reasonably well are three fully separate things....

setting the config higher has a (not super large but still) performance and memory cost so setting much higher than you can boot/test is just wasting cycles and memory...

(will clear linux go higher than 512... I'm sure we will at some point; this was just the easy safe quick fix)

[coder]

setting the variable high, and actually booting and working reasonably well are three fully separate things....

The part of the article I quoted claims other vendors actually use such a value. It would be interesting to know who.

[Michael]

The part of the article I quoted claims other vendors actually use such a value. It would be interesting to know who.

On the Fedora system I am typing from...

grep NR_CPUS /boot/config-5.19.16-100.fc35.x86_64
CONFIG_NR_CPUS=8192

[arjan_intel]

On the Fedora system I am typing from...

grep NR_CPUS /boot/config-5.19.16-100.fc35.x86_64
CONFIG_NR_CPUS=8192

sorry I was not very precise. you can boot with a higher setting on a small system. question is if it'll boot on a system with actual 8192 cpus

[Michael]

sorry I was not very precise. you can boot with a higher setting on a small system. question is if it'll boot on a system with actual 8192 cpus

Right, yes, I agree. My comment was intended in response to coder's "The part of the article I quoted claims other vendors actually use such a value. It would be interesting to know who." as an example of a distribution vendor kernel (Fedora) defaulting to the high value.

[Rallos Zek]

Wow we're about 2 generations away from hitting 1990's IRIX cpu core counts (1024+) on Linux.

You're over 15 years of being out of touch with the real word.

https://www.thefreelibrary.com/LARGEST+LINUX+IMAGE+ACHIEVED+ON+SGI+ALTIX+4700+BLADE+SERVER.-a0148365609