On 07/15/2013 04:14 PM, Josh Boyer wrote:
On Mon, Jul 15, 2013 at 1:21 PM, Prarit Bhargava
<prarit(a)redhat.com> wrote:
> I've done some testing across various systems (both "large" and
"small").
> 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.
1.1M isn't small. We recently declined to build btrfs into the kernel
because it increased the overall memory usage by a similar amount.
Also, we regularly see users and bug reports still in the 2G range.
OOC what was the objection to 1M? Is there some lower limit I should be
concerned about?
While it's not an apples to apples comparison, far more Fedora
users
are going to be using btrfs than > 128 CPUs. I'm not saying no
immediately, but I'm kinda dubious as to the benefits for Fedora.
We're already exceeding 128 cpus on a regular basis (or at least I am). Getting
testing in the upper range only improves Fedora ... IMO.
P.
josh