[RFC PATCH 0/4] pre sort pages on lruvec in pagevec

From: Alex Shi
Date: Fri Dec 25 2020 - 05:04:21 EST


This idea was tried on per memcg lru lock patchset v18, and had a good
result, about 5%~20+% performance gain on lru lock busy benchmarks,
like case-lru-file-readtwice.

But on the latest kernel, I can not reproduce the result on my box.
Also I can not reproduce Tim's performance gain too on my box.

So I don't know if it's workable in some scenario, just sent out if
someone has interesting...

Alex Shi (4):
mm/swap.c: pre-sort pages in pagevec for pagevec_lru_move_fn
mm/swap.c: bail out early for no memcg and no numa
mm/swap.c: extend the usage to pagevec_lru_add
mm/swap.c: no sort if all page's lruvec are same

Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

mm/swap.c | 118 +++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 91 insertions(+), 27 deletions(-)

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2.29.GIT