Re: [PATCH] mm/vmstat: Reduce zone lock hold time when reading /proc/pagetypeinfo

[Michal Hocko]

On Thu 24-10-19 07:11:52, Qian Cai wrote:
> 
> 
> > On Oct 24, 2019, at 3:42 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> > 
> > It's been useful for debugging memory fragmentation problems and we do
> > not have anything that would provide a similar information. Considering
> 
> Actually, zoneinfo and buddyinfo are somewhat similar to it. Why
> the extra information in pagetypeinfo is still useful in debugging
> todayâs real-world scenarios?

Because the migrate type is the information that helps to understand
fragmentation related issues. I am pretty sure Vlastimil would tell you
much more.

> > that making it root only is trivial and reducing the lock hold times
> > likewise I do not really see any strong reason to dump it at this
> > moment.
> 
> There is no need to hurry this, and clearly this is rather a good
> opportunity to discuss the consolidation of memory fragmentation
> debugging to ease the maintenance in long term.

Right. I think we should address the issue at hands first and then
handle any possible consolidations.

-- 
Michal Hocko
SUSE Labs