[v4 0/6] optimize memory hotplug

From: Pavel Tatashin
Date: Thu Feb 15 2018 - 12:00:00 EST


Changelog:
v3 - v4
Addressed comments from Ingo Molnar and from Michal Hocko
Splitted 4th patch into three patches
Instead of using section table to save node ids, saving node id in
the first page of every section.

v2 - v3
Fixed two issues found during testing
Addressed Kbuild warning reports

v1 - v2
Added struct page poisoning checking in order to verify that
struct pages are never accessed until initialized during memory
hotplug

This patchset:
- Improves hotplug performance by eliminating a number of
struct page traverses during memory hotplug.

- Fixes some issues with hotplugging, where boundaries
were not properly checked. And on x86 block size was not properly aligned
with end of memory

- Also, potentially improves boot performance by eliminating condition from
__init_single_page().

- Adds robustness by verifying that that struct pages are correctly
poisoned when flags are accessed.

The following experiments were performed on Xeon(R) CPU E7-8895 v3 @ 2.60GHz
with 1T RAM:

booting in qemu with 960G of memory, time to initialize struct pages:

no-kvm:
TRY1 TRY2
BEFORE: 39.433668 39.39705
AFTER: 36.903781 36.989329

with-kvm:
BEFORE: 10.977447 11.103164
AFTER: 10.929072 10.751885

Hotplug 896G memory:
no-kvm:
TRY1 TRY2
BEFORE: 848.740000 846.910000
AFTER: 783.070000 786.560000

with-kvm:
TRY1 TRY2
BEFORE: 34.410000 33.57
AFTER: 29.810000 29.580000

Pavel Tatashin (6):
mm/memory_hotplug: enforce block size aligned range check
x86/mm/memory_hotplug: determine block size based on the end of boot
memory
mm: uninitialized struct page poisoning sanity checking
mm/memory_hotplug: optimize probe routine
mm/memory_hotplug: don't read nid from struct page during hotplug
mm/memory_hotplug: optimize memory hotplug

arch/x86/mm/init_64.c | 33 +++++++++++++++++++++++++++++----
drivers/base/memory.c | 38 +++++++++++++++++++++-----------------
drivers/base/node.c | 22 +++++++++++++++-------
include/linux/mm.h | 4 +++-
include/linux/node.h | 4 ++--
include/linux/page-flags.h | 22 +++++++++++++++++-----
mm/memblock.c | 2 +-
mm/memory_hotplug.c | 36 ++++++++++++++----------------------
mm/page_alloc.c | 28 ++++++++++------------------
mm/sparse.c | 9 ++++++++-
10 files changed, 120 insertions(+), 78 deletions(-)

--
2.16.1