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

[Qian Cai]

On Wed, 2019-10-23 at 11:01 -0400, Waiman Long wrote:
> On 10/23/19 10:48 AM, Qian Cai wrote:
> > > > this still isn't a bulletproof fix.  Maybe just terminate the list
> > > > walk if freecount reaches 1024.  Would anyone really care?
> > > > 
> > > > Sigh.  I wonder if anyone really uses this thing for anything
> > > > important.  Can we just remove it all?
> > > > 
> > > 
> > > Removing it will be a breakage of kernel API.
> > 
> > Who cares about breaking this part of the API that essentially nobody will use
> > this file?
> > 
> 
> There are certainly tools that use /proc/pagetypeinfo and this is how
> the problem is found. I am not against removing it, but we have to be
> careful and deprecate it in way that minimize user impact.

What are those tools?