[v2,0/4] add KSM selftests

Message

Zhansaya Bagdauletkyzy July 14, 2021, 8:56 a.m. UTC

Introduce selftests to validate the functionality of KSM. The tests are
run on private anonymous pages. Since some KSM tunables are modified,
their starting values are saved and restored after testing. At the
start, run is set to 2 to ensure that only test pages will be merged (we
assume that no applications make madvise syscalls in the background). If
KSM config not enabled, all tests will be skipped.

Zhansaya Bagdauletkyzy (4):
  selftests: vm: add KSM merge test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM merging across nodes test

v1 -> v2:
- add a test to check KSM unmerging
- add a test to check merging of zero pages
- add a test to check merging in different NUMA nodes
- include command line options for each test
- new options to specify use_zero_pages and merge_across_nodes
- run each test case in run_vmtests.sh
- add some helper functions to make the code more compact:
  allocate_memory(), ksm_do_scan(), ksm_merge_pages()

 tools/testing/selftests/vm/.gitignore     |   1 +
 tools/testing/selftests/vm/Makefile       |   3 +
 tools/testing/selftests/vm/ksm_tests.c    | 516 ++++++++++++++++++++++
 tools/testing/selftests/vm/run_vmtests.sh |  96 ++++
 4 files changed, 616 insertions(+)
 create mode 100644 tools/testing/selftests/vm/ksm_tests.c

Comments

Andrew Morton July 14, 2021, 10:51 p.m. UTC | #1

On Wed, 14 Jul 2021 14:56:01 +0600 Zhansaya Bagdauletkyzy <[e-mail]> wrote:

> Introduce selftests to validate the functionality of KSM.

ooh, nice, thanks!  Now I'm wondering why I didn't ask for this when
KSM was initially merged...