Re: [PATCH 0/4] selftests/mm: replace transhuge-stress with a THP compaction selftest

[Dev Jain <dev.jain@arm.com>]

On 12/11/26 2:32 pm, Sarthak Sharma wrote:
> transhuge-stress is a stressor tool that repeatedly
> allocates and splits THPs till a specified duration. If the
> duration elapses, the test passes and fails only if a setup or
> system call fails.
> 
> This is not how a test residing in selftests/mm is supposed to
> behave. So remove it and add a new functional test called
> thp-compaction.c, that allocates THPs as much as it can,
> splits those THPs keeping one page retained and discarding
> others, and then retries allocating THPs, which will test
> if THP compaction is working fine. If we are able to recover
> more than half of the initial THPs, the test passes. Otherwise
> it fails.
> 
> This was suggested by David earlier [1].
> 

Isn't compaction_test.c already sort-of doing what you are trying to
do here?


> Patch 1 removes the current transhuge-stress. Patch 2 adds a check to see
> if PFNs are being masked due to no CAP_SYS_ADMIN in the initial user namespace.
> Patch 3 factors out THP split helpers from split_huge_page_test.c to vm_util.c.
> Patch 4 adds the
> new test.
> 
> [1] https://lore.kernel.org/all/94ace42d-8d60-4475-953e-74fb3dc23774@kernel.org/
> 
> Sarthak Sharma (4):
>   selftests/mm: remove transhuge-stress
>   selftests/mm: detect masked PFNs in allocate_transhuge()
>   selftests/mm: factor out THP split helpers
>   selftests/mm: add a THP compaction selftest
> 
>  MAINTAINERS                                   |   2 +-
>  tools/testing/selftests/mm/Makefile           |   2 +-
>  tools/testing/selftests/mm/ksm_tests.c        |  26 ++-
>  tools/testing/selftests/mm/run_vmtests.sh     |   2 +-
>  .../selftests/mm/split_huge_page_test.c       |  45 +---
>  tools/testing/selftests/mm/thp-compaction.c   | 215 ++++++++++++++++++
>  tools/testing/selftests/mm/transhuge-stress.c | 146 ------------
>  tools/testing/selftests/mm/vm_util.c          |  65 ++++++
>  tools/testing/selftests/mm/vm_util.h          |   6 +
>  9 files changed, 313 insertions(+), 196 deletions(-)
>  create mode 100644 tools/testing/selftests/mm/thp-compaction.c
>  delete mode 100644 tools/testing/selftests/mm/transhuge-stress.c
>