Re: [MM] Make mm counters per cpu instead of atomic

Christoph Lameter
2009-11-05T18:02:57Z

On Thu, 5 Nov 2009, KAMEZAWA Hiroyuki wrote:

> Hmm, I don't fully understand _new_ percpu but...
> In logical (even if not realistic), x86-32 supports up to 512 ? cpus in Kconfig.
> BIGSMP.

x86-32 only supports 32 processors. Plus per cpu areas are only allocated
for the possible processors.

> Then, if 65536 process runs, this consumes
>
> 65536(nr_proc) * 8 (size) * 512(cpus) = 256MBytes.

With 32 possible cpus this results in 16m of per cpu space use.