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

[Waiman Long]

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.

Cheers,
Longman