[PATCH v2 0/3] selftests/mm: virtual_address_range: Reduce memory usage and avoid VVAR access

Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx> · Fri, 10 Jan 2025 14:05:49 +0100

The selftest started failing since commit e93d2521b27f
("x86/vdso: Split virtual clock pages into dedicated mapping")
was merged. While debugging I stumbled upon some memory usage
optimizations.

With these test now runs on a VM with only 60MiB of memory.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
---
Changes in v2:
- Drop /dev/null usage
- Avoid overcommit restrictions by dropping PROT_WRITE
- Avoid high memory usage due to PTEs
- Link to v1: https://lore.kernel.org/r/20250107-virtual_address_range-tests-v1-0-3834a2fb47fe@xxxxxxxxxxxxx

---
Thomas Weißschuh (3):
      selftests/mm: virtual_address_range: mmap() without PROT_WRITE
      selftests/mm: virtual_address_range: Unmap chunks after validation
      selftests/mm: virtual_address_range: Avoid reading VVAR mappings

 tools/testing/selftests/mm/config                  |  1 +
 tools/testing/selftests/mm/virtual_address_range.c | 34 +++++++++++++++++++---
 2 files changed, 31 insertions(+), 4 deletions(-)
---
base-commit: 32af4d2269d20fe2f8d32aaa456cad8e40abd365
change-id: 20250107-virtual_address_range-tests-95843766fa97

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>