Re: [PATCH resend 3/3] mm: fix LRU balancing effect of new transparent huge pages

[Andrew Morton]

On Wed, 27 May 2020 15:41:48 -0400 Johannes Weiner <hannes@xxxxxxxxxxx> wrote:

> On Wed, May 27, 2020 at 11:29:58AM -0700, Shakeel Butt wrote:
> > From: Johannes Weiner <hannes@xxxxxxxxxxx>
> > 
> > Currently, THP are counted as single pages until they are split right
> > before being swapped out. However, at that point the VM is already in
> > the middle of reclaim, and adjusting the LRU balance then is useless.
> > 
> > Always account THP by the number of basepages, and remove the fixup
> > from the splitting path.
> > 
> > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> > Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> 
> This is now already in mm as part of the "mm: balance LRU lists based
> on relative thrashing" series that I sent out last week and where it
> was originally from.

Yup.  I hope [1/3] and [2/3] weren't urgent?  Due to a horrid merge
mismatchmishmashmess I've staged them behind lots of other things,
notably

thp/khugepaged improvements and CoW semantics
http://lkml.kernel.org/r/20200416160026.16538-1-kirill.shutemov@xxxxxxxxxxxxxxx

and mm: memcontrol: charge swapin pages on instantiation
http://lkml.kernel.org/r/20200508183105.225460-1-hannes@xxxxxxxxxxx

and mm: balance LRU lists based on relative thrashing
http://lkml.kernel.org/r/20200520232525.798933-1-hannes@xxxxxxxxxxx