[0/2] arm64/mm: Enable color zero pages

Message

Gavin Shan Sept. 16, 2020, 3:25 a.m. UTC

The feature of color zero pages isn't enabled on arm64, meaning all
read-only (anonymous) VM areas are backed up by same zero page. It
leads pressure to L1 (data) cache on reading data from them. This
tries to enable color zero pages.

PATCH[1/2] decouples the zero PGD table from zero page
PATCH[2/2] allocates the needed zero pages according to L1 cache size

Gavin Shan (2):
  arm64/mm: Introduce zero PGD table
  arm64/mm: Enable color zero pages

 arch/arm64/include/asm/cache.h       | 22 +++++++++++++++++
 arch/arm64/include/asm/mmu_context.h |  6 ++---
 arch/arm64/include/asm/pgtable.h     | 11 +++++++--
 arch/arm64/kernel/cacheinfo.c        | 34 +++++++++++++++++++++++++++
 arch/arm64/kernel/setup.c            |  2 +-
 arch/arm64/kernel/vmlinux.lds.S      |  4 ++++
 arch/arm64/mm/init.c                 | 35 ++++++++++++++++++++++++++++
 arch/arm64/mm/mmu.c                  |  7 ------
 arch/arm64/mm/proc.S                 |  2 +-
 9 files changed, 109 insertions(+), 14 deletions(-)