[PATCH mm-stable v2 0/3] mm/ksm: improve PR_SET_MEMORY_MERGE=0 handling and cleanup disabling KSM

David Hildenbrand
2023-04-22T20:55:29Z

This is a follow-up to [1]:
[PATCH v9 0/3] mm: process/cgroup ksm support

which is now in mm-stable. Ideally we'd get at least patch #1 into the
same kernel release as [1], so the semantics of setting
PR_SET_MEMORY_MERGE=0 are unchanged between kernel versions.

(1) Make PR_SET_MEMORY_MERGE=0 unmerge pages like setting MADV_UNMERGEABLE
does, (2) add a selftest for it and (3) factor out disabling of KSM from
s390/gmap code.

v1 -> v2:
- "mm/ksm: unmerge and clear VM_MERGEABLE when setting
PR_SET_MEMORY_MERGE=0"
-> Cleanup one if/else
-> Add doc for ksm_disable_merge_any()
- Added ACKs

[1] https://lkml.kernel.org/r/20230418051342.1919757-1-shr@devkernel.io

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stefan Roesch <shr@devkernel.io>
Cc: Rik van Riel <riel@surriel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>

David Hildenbrand (3):
mm/ksm: unmerge and clear VM_MERGEABLE when setting
PR_SET_MEMORY_MERGE=0
selftests/ksm: ksm_functional_tests: add prctl unmerge test
mm/ksm: move disabling KSM from s390/gmap code to KSM code

arch/s390/mm/gmap.c | 20 +-----
include/linux/ksm.h | 7 ++
kernel/sys.c | 12 +---
mm/ksm.c | 70 +++++++++++++++++++
.../selftests/mm/ksm_functional_tests.c | 46 ++++++++++--
5 files changed, 121 insertions(+), 34 deletions(-)

--
2.40.0