[RFC PATCH V4 0/1] mm: add last level page table numa info to /proc/pid/numa_pgtable

[Xin Hao <xhao@linux.alibaba.com>]

In many data center servers, the shared memory architectures is
Non-Uniform Memory Access (NUMA), remote numa node data access
often brings a high latency problem, but what we are easy to ignore
is that the page table remote numa access, It can also leads to a
performance degradation.

So there add a new interface in /proc, This will help developers to
get more info about performance issues if they are caused by cross-NUMA.

V4 -> V3
1, Add some detects and spinlock when operating PMD page as Baolin Wang advised.

V2 -> V3
1, Fix compile warning bug.

V1 -> V2
1, As Matthew Wilcox advise, Simplify the code.
2, Do some codes format fix.

V3: https://lore.kernel.org/linux-mm/20220801032704.64356-1-xhao@linux.alibaba.com/
V2: https://lore.kernel.org/linux-mm/20220731155223.60238-1-xhao@linux.alibaba.com/
V1: https://lore.kernel.org/linux-mm/YuVqdcY8Ibib2LJa@casper.infradead.org/T/


Xin Hao (1):
  mm: add last level page table numa info to /proc/pid/numa_pgtable

 fs/proc/base.c     |  2 ++
 fs/proc/internal.h |  1 +
 fs/proc/task_mmu.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+)

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2.31.0