Re: Debian stock kernel config -- CONFIG_NR_CPUS=32?
On Thu, Oct 21, 2010 at 8:15 PM, Andrew Reid <email@example.com> wrote:
> But I'm curious if anyone on the list knows the rationale for
> distributing kernels with this set to 32. Is that just a
> reasonable number that's never been updated? Or is there some
> complication that arises after 32 cores, and should I be more
> careful about tuning other parameters?
I've always set the number of cores to exactly how many I have x2 when
I roll my own, which on my puny systems is either 4 or 8. I seem to
recall reading that there is a slight performance hit for every core
you support. Or was it memory hit? Or was that a bong hit I'm thinking
I really can't remember, but I think it was in Greg's "Linux Kernel In
A Nutshell" book, by O'Reilly, though free to download.
This exchange seems appropriate now...
Peter Griffin: "It's true. I read it in a book somewhere"
Brian Griffin: "Are you sure it was a book? Are you sure it wasn't... nothing?"