Re: [PATCH RFC] mm, proc: add PcpFree to meminfo

Kefeng Wang
2022-08-19T01:08:47Z

On 2022/8/19 5:07, Dave Hansen wrote:
> On 8/17/22 00:16, Kefeng Wang wrote:
>> On 2022/8/16 16:44, Kefeng Wang wrote:
>>> From: Liu Shixin <liushixin2@huawei.com>
>>>
>>> The page on pcplist could be used, but not counted into memory free or
>>> avaliable, and pcp_free is only showed by show_mem(). Since commit
>>> d8a759b57035 ("mm, page_alloc: double zone's batchsize"), there is a
>>> significant decrease in the display of free memory, with a large number
>>> of cpus and nodes, the number of pages in the percpu list can be very
>>> large, so it is better to let user to know the pcp count.
>> Add more experts according to commit d8a759b57035，
>> any advice would be much appreciated，thanks.
> Adding a new meminfo field seems like overkill. I'd just make this a
> part of MemFree if anything.
I like this way too.
> Also, some actual data would be nice here. Like:
>
> Before commit d8a759b57035, the maximum amount of pages in the
> pcp lists was theoretically $FOO MB. After the patch, the lists
> can hold $BAR MB. It has been observed to be $BAZ MB in
> practice.
>
> This was all on a system with $X memory NUMA nodes and $Y CPUs.
>
> .

Same question in [1],  will repost with update, thanks.

[1]