[0/2] Allow high order pages to be stored on PCP

Message

Mel Gorman June 3, 2021, 8:46 a.m. UTC

The per-cpu page allocator (PCP) only handles order-0 pages. With the
series "Use local_lock for pcp protection and reduce stat overhead"
and "Calculate pcp->high based on zone sizes and active CPUs", it's now
feasible to store high-order pages on PCP lists.

This small series allows PCP to store "cheap" orders where cheap is
determined by PAGE_ALLOC_COSTLY_ORDER and THP-sized allocations. For
convenience, the series with the prerequisites are at

git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-pcphighorder-v1r7

The baseline is 5.13-rc2 because that is what I tested with but the
patches rebase cleanly to mmots.

 include/linux/mmzone.h |  20 ++++-
 mm/internal.h          |   2 +-
 mm/page_alloc.c        | 171 +++++++++++++++++++++++++++++------------
 mm/swap.c              |   2 +-
 4 files changed, 141 insertions(+), 54 deletions(-)