Re: [PATCH v1 0/4]mm: convert totalram_pages, totalhigh_pages and managed pages to atomic

[Arun KS]

On 2018-11-07 05:52, Andrew Morton wrote:
> On Fri, 26 Oct 2018 16:30:58 +0530 Arun KS <arunks@xxxxxxxxxxxxxx> 
> wrote:
>
> > This series convert totalram_pages, totalhigh_pages and
> > zone->managed_pages to atomic variables.
>
> The whole point appears to be removal of managed_page_count_lock, yes?
>
> Why?  What is the value of this patchset?  If "performance" then are 
> any
> measurements available?

Hello Andrew,

https://patchwork.kernel.org/patch/10670787/
In version 2, I have added motivation behind this conversion. Pasting 
same here,

totalram_pages, zone->managed_pages and totalhigh_pages updates are 
protected by managed_page_count_lock, but readers never care about it. 
Convert these variables to atomic to avoid readers potentially seeing a 
store tear. I don't think we have a performance improvement here.

Regards,
Arun