Comment by globular-toast
2 years ago
I used to work on a supercomputer with 128 cores on it that ran Linux (I actually seem to remember it had 256 cores, but someone said the kernel had a limit of 128). This was less than 15 years ago. There were surely many systems just like that one. Does that mean the kernel had been patched? But nobody thought to push that patch upstream?
Reading the other comments here it seems the title is stupid and wrong and my suspicion that this can't be right was correct.
There’s probably nothing to patch: from my understanding this does not actually affect the scaling of the OS, it affects the throughput on heavily loaded systems, as min_slice is the delay before which a task can’t be preempted.
So it’s only relevant if the system has more tasks than cores, and if you ignore priorities and pinning. I assume these are the sort of mistakes people working with supercomputers would not be making, and residency would be a very carefully monitored to ensure the system is not thrashing.
You didn't even have to have a supercomputer as common Opteron systems pretty much had more than 8 cores. So, someone would definitely notice that. Especially AMD. :)