Re: [PATCH v2] proc: add percpu populated pages count to meminfo

From: Vlastimil Babka
Date: Wed Aug 08 2018 - 03:53:38 EST

On 08/07/2018 08:47 PM, Dennis Zhou wrote:
> From: "Dennis Zhou (Facebook)" <dennisszhou@xxxxxxxxx>
> Currently, percpu memory only exposes allocation and utilization
> information via debugfs. This more or less is only really useful for
> understanding the fragmentation and allocation information at a
> per-chunk level with a few global counters. This is also gated behind a
> config. BPF and cgroup, for example, have seen an increase use causing
> increased use of percpu memory. Let's make it easier for someone to
> identify how much memory is being used.
> This patch adds the "Percpu" stat to meminfo to more easily look up how
> much percpu memory is in use. This number includes the cost for all
> allocated backing pages and not just isnight at the a unit, per chunk
> level. Metadata is excluded. I think excluding metadata is fair because
> the backing memory scales with the numbere of cpus and can quickly
> outweigh the metadata. It also makes this calculation light.
> Signed-off-by: Dennis Zhou <dennisszhou@xxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>