[0/2] khugepaged: collapse pmd for pte-mapped THP

Message

Song Liu July 29, 2019, 5:43 a.m. UTC

This set is the newer version of 5/6 and 6/6 of [1]. v9 of 1-4 of
the work [2] was recently picked by Andrew.

Patch 1 enables khugepaged to handle pte-mapped THP. These THPs are left
in such state when khugepaged failed to get exclusive lock of mmap_sem.

Patch 2 leverages work in 1 for uprobe on THP. After [2], uprobe only
splits the PMD. When the uprobe is disabled, we get pte-mapped THP.
After this set, these pte-mapped THP will be collapsed as pmd-mapped.

[1] https://lkml.org/lkml/2019/6/23/23
[2] https://www.spinics.net/lists/linux-mm/msg185889.html

Song Liu (2):
  khugepaged: enable collapse pmd for pte-mapped THP
  uprobe: collapse THP pmd after removing all uprobes

 include/linux/khugepaged.h |  15 ++++
 kernel/events/uprobes.c    |   9 +++
 mm/khugepaged.c            | 136 +++++++++++++++++++++++++++++++++++++
 3 files changed, 160 insertions(+)

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2.17.1