Re: mm: pages are not freed from lru_add_pvecs after process termination

From: Dave Hansen
Date: Mon May 02 2016 - 11:49:31 EST


On 05/02/2016 08:01 AM, Kirill A. Shutemov wrote:
> On Mon, May 02, 2016 at 04:39:35PM +0200, Vlastimil Babka wrote:
>> On 04/27/2016 07:11 PM, Dave Hansen wrote:
>>> 6. Perhaps don't use the LRU pagevecs for large pages. It limits the
>>> severity of the problem.
>>
>> I think that makes sense. Being large already amortizes the cost per base
>> page much more than pagevecs do (512 vs ~22 pages?).
>
> We try to do this already, don't we? Any spefic case where we have THPs on
> pagevecs?

Lukas was hitting this on a RHEL 7 era kernel. In his kernel at least,
I'm pretty sure THP's were ending up on pagevecs. Are you saying you
don't think we're doing that any more?