Re: Percpu variables, benchmarking, and performance weirdness

[Tejun Heo]

On Fri, Dec 20, 2019 at 08:22:02AM -0800, Eric Dumazet wrote:
> I definitely seen expensive per-cpu updates in the stack.
> (SNMP counters, or per-cpu stats for packets/bytes counters)
> 
> It might be nice to have an option to use 2M pages.
> 
> (I recall sending some patches in the past about using high-order pages for vmalloc,
> but this went nowhere)

Yeah, the percpu allocator implementation is half-way prepared for
that.  There just hasn't been a real need for that yet.  If this
actually is a difference coming from tlb pressure, this might be it, I
guess?

Thanks.

-- 
tejun