Mshare is a developing feature proposed by Anthony Yznaga and Khalid Aziz that enables sharing of PTEs across processes. The V3 patch set has been posted for review:
https://lore.kernel.org/linux-mm/20250820010415.699353-1-anthony.yznaga@orac...
This patch set adds selftests to exercise and demonstrate basic functionality of mshare.
The initial tests use open, ioctl, and mmap syscalls to establish a shared memory mapping between two processes and verify the expected behavior.
Additional tests are included to check interoperability with swap and Transparent Huge Pages.
Future work will extend coverage to other use cases such as integration with KVM and more advanced scenarios.
This series is intended to be applied on top of mshare V3, which is based on mm-new (2025-08-15).
Yongting Lin (8): mshare: Add selftests mshare: selftests: Adding config fragment mshare: selftests: Add some helper function for mshare filesystem mshare: selftests: Add test case shared memory mshare: selftests: Add test case ioctl unmap mshare: selftests: Add some helper functions for reading and controlling cgroup mshare: selftests: Add test case to demostrate the swaping of mshare memory mshare: selftests: Add test case to demostrate that mshare doesn't support THP
tools/testing/selftests/mshare/.gitignore | 3 + tools/testing/selftests/mshare/Makefile | 7 + tools/testing/selftests/mshare/basic.c | 108 ++++++++++ tools/testing/selftests/mshare/config | 1 + tools/testing/selftests/mshare/memory.c | 82 +++++++ tools/testing/selftests/mshare/util.c | 251 ++++++++++++++++++++++ 6 files changed, 452 insertions(+) create mode 100644 tools/testing/selftests/mshare/.gitignore create mode 100644 tools/testing/selftests/mshare/Makefile create mode 100644 tools/testing/selftests/mshare/basic.c create mode 100644 tools/testing/selftests/mshare/config create mode 100644 tools/testing/selftests/mshare/memory.c create mode 100644 tools/testing/selftests/mshare/util.c