Re: [PATCH i-g-t v10 0/8] tests/xe: Add purgeable memory madvise tests for system allocator

[Alex Hung <alex.hung@amd.com>]

Patch 2 & 3 seem to cause the following compilation failures on CI's 
build:tests-debian-meson-armhf.

See https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/jobs/97703144


../tests/intel/xe_madvise.c: In function ‘test_purged_mmap_blocked’:
../tests/intel/xe_madvise.c:201:20: error: cast from pointer to integer 
of different size [-Werror=pointer-to-int-cast]
   201 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |                    ^
../lib/igt_core.h:796:20: note: in definition of macro ‘igt_assert_cmpu64’
   796 |   uint64_t __n1 = (n1), __n2 = (n2); \
       |                    ^~
../tests/intel/xe_madvise.c:201:2: note: in expansion of macro 
‘igt_assert_eq_u64’
   201 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |  ^~~~~~~~~~~~~~~~~
../tests/intel/xe_madvise.c:201:35: error: cast from pointer to integer 
of different size [-Werror=pointer-to-int-cast]
   201 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |                                   ^
../lib/igt_core.h:796:33: note: in definition of macro ‘igt_assert_cmpu64’
   796 |   uint64_t __n1 = (n1), __n2 = (n2); \
       |                                 ^~
../tests/intel/xe_madvise.c:201:2: note: in expansion of macro 
‘igt_assert_eq_u64’
   201 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |  ^~~~~~~~~~~~~~~~~
../tests/intel/xe_madvise.c: In function ‘test_dontneed_before_mmap’:
../tests/intel/xe_madvise.c:343:20: error: cast from pointer to integer 
of different size [-Werror=pointer-to-int-cast]
   343 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |                    ^
../lib/igt_core.h:796:20: note: in definition of macro ‘igt_assert_cmpu64’
   796 |   uint64_t __n1 = (n1), __n2 = (n2); \
       |                    ^~
../tests/intel/xe_madvise.c:343:2: note: in expansion of macro 
‘igt_assert_eq_u64’
   343 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |  ^~~~~~~~~~~~~~~~~
../tests/intel/xe_madvise.c:343:35: error: cast from pointer to integer 
of different size [-Werror=pointer-to-int-cast]
   343 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |                                   ^
../lib/igt_core.h:796:33: note: in definition of macro ‘igt_assert_cmpu64’
   796 |   uint64_t __n1 = (n1), __n2 = (n2); \
       |                                 ^~
../tests/intel/xe_madvise.c:343:2: note: in expansion of macro 
‘igt_assert_eq_u64’
   343 |  igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
       |  ^~~~~~~~~~~~~~~~~

On 4/14/26 00:16, Arvind Yadav wrote:
> This series adds IGT tests for the purgeable memory madvise functionality
> in the XE driver's system allocator path.
> 
> Purgeable memory allows userspace to mark buffer objects as DONTNEED,
> making them eligible for kernel reclamation under memory pressure. This
> is critical for mobile and memory-constrained platforms to prevent OOM
> conditions while managing temporary or regeneratable GPU data.
> 
> The test suite validates:
> - Basic purgeable lifecycle (WILLNEED -> DONTNEED -> PURGED)
> - "Once purged, always purged" semantics (i915 compatibility)
> - Per-VMA purgeable state tracking for shared buffers
> - CPU fault handling on purged BOs (SIGBUS/SIGSEGV)
> - GPU execution with purged memory and scratch page protection
> - Proper state transitions across multiple VMs
> 
> Purgeable Memory States:-
>   - **WILLNEED (0)**: Memory is actively needed, kernel should not
>                       reclaim it.
>   - **DONTNEED (1)**: Application doesn't need this memory right now,
>                       kernel can reclaim it if needed
> 
> Retained Value
>   When querying purgeable state, the kernel returns:
>   - retained = 1: Memory is still present (not purged)
>   - retained = 0: Memory was purged/reclaimed
> 
> Kernel dependency: https://patchwork.freedesktop.org/series/156651/
>   
> Test Cases :
>    1. dontneed-before-mmap
>          Purpose: Validate that mmap fails on dontneed BO
> 
>    2. purged-mmap-blocked
>          Purpose: Validate that mmap fails on already-purged
>        
>    3. dontneed-after-mmap
>          Purpose: Validate that accessing an existing mapping of purged memory
>                   triggers SIGBUS/SIGSEGV.
> 
>    4. dontneed-before-exec
>          Purpose: Validate GPU execution on purgeable BO (before it's used).
> 
>    5. dontneed-after-exec
>          Purpose: Validate that previously-used BO can be purged and becomes
>                   inaccessible.
> 
>    6. per-vma-tracking
>          Purpose: Validate per-VMA purgeable state tracking
> 
>    7. per-vma-protection
>          Purpose: Validate that WILLNEED VMA protects BO from purging during
>                   GPU operations.
> v2:
>     - Move tests from xe_exec_system_allocator.c to dedicated
>       xe_madvise.c (Thomas Hellström).
>     - Fix trigger_memory_pressure to use scalable overpressure
>      (25% of VRAM, minimum 64MB instead of fixed 64MB). (Pravalika)
>     - Add MAP_FAILED check in trigger_memory_pressure.
>     - Touch all pages in allocated chunks, not just first 4KB. (Pravalika)
>     - Add 100ms sleep before freeing BOs to allow shrinker time
>       to process memory pressure.  (Pravalika)
>     - Rename 'bo2' to 'handle' for clarity in trigger_memory_pressure.(Pravalika)
>     - Add NEEDS_VISIBLE_VRAM flag to purgeable_setup_simple_bo
>       for consistent CPU mapping support on discrete GPUs.  (Pravalika)
>     - Add proper NULL mmap handling in test_dontneed_before_mmap
>        with cleanup and early return.  (Pravalika)
> 
> v3:
>     - Added separate commits for each individual test case. (Pravalika)
> 
> v4:
>     - Move unmap outside the block. (Pravalika)
>     - Added proper resource cleanup before calling igt_skip(). (Nishit)
>     - Added assertion for xe_bo_map. (Nishit)
>     - Now using sync[0] consistently. (Nishit)
>     - Added clarifying comment. (Nishit)
> 
> v5:
>    - Document DONTNEED BO access blocking behavior to prevent undefined
>      behavior and clarify uAPI contract (Thomas, Matt)
>    - Add query flag DRM_XE_QUERY_CONFIG_FLAG_HAS_PURGING_SUPPORT for
>      feature detection. (Jose)
>    - For DONTNEED BO's mmap offset ioctl blocked with -EBUSY.
>    - Rename retained to retained_ptr. (Jose)
>    - Add new subtest purged-mmap-blocked.
> 
> v6:
>    - Support iGPU in trigger_memory_pressure() by using total system RAM
>      as pressure baseline; raise overpressure to 50% to force shrinker.
>    - DONTNEED mmap blocking now enforced at mmap() time (xe_gem_object_mmap),
>      not at DRM_IOCTL_XE_GEM_MMAP_OFFSET. Update dontneed-before-mmap and
>      purged-mmap-blocked accordingly.
>    - Fix graceful skip (instead of fail) in per-vma-tracking and
>      per-vma-protection when purge cannot be induced. (Nishit)
> 
> v7:
>    - Commit message updated with kernel UAPI details (Nishit)
>    - Moved trigger_memory_pressure(), purgeable_mark_and_verify_purged()
>      and sigtrap() in 4/9 and other patch. (Nishit)
>    - Use xe_has_vram() instead of checking xe_visible_vram_size() > 0 for
>      clearer dGPU/iGPU detection. (Nishit)
>    - Fix purgeable_mark_and_verify_purged(): handle retained == 0 from
>      DONTNEED (BO already purged) as success instead of incorrectly
>      returning false. (Nishit)
>    - Drop unused vm parameter from trigger_memory_pressure(). (Nishit)
>    - Mentioned this new ioctl instead of __xe_vm_madvise(). (Nishit)
> 
> v8:
>    - rebased.
>    - Drop this "[i-g-t,v7,1/9] drm-uapi/xe_drm: Sync with Add UAPI
>      support for purgeable buffer objects" patch. (Kamil)
> 
> v9:
>    - Added Reviewed-by tags. (Nishit)
> 
> v10:
>    - iGPU: use igt_purge_vm_caches() to trigger shrinker directly
>      instead of flooding system RAM (avoids OOM on low-memory machines).
>    - Simplified comments in trigger_memory_pressure().
> 
> Arvind Yadav (8):
>    lib/xe: Add purgeable memory ioctl support
>    tests/intel/xe_madvise: Add dontneed-before-mmap subtest
>    tests/intel/xe_madvise: Add purged-mmap-blocked subtest
>    tests/intel/xe_madvise: Add dontneed-after-mmap subtest
>    tests/intel/xe_madvise: Add dontneed-before-exec subtest
>    tests/intel/xe_madvise: Add dontneed-after-exec subtest
>    tests/intel/xe_madvise: Add per-vma-tracking subtest
>    tests/intel/xe_madvise: Add per-vma-protection subtest
> 
>   lib/xe/xe_ioctl.c        |  33 ++
>   lib/xe/xe_ioctl.h        |   2 +
>   tests/intel/xe_madvise.c | 829 +++++++++++++++++++++++++++++++++++++++
>   tests/meson.build        |   1 +
>   4 files changed, 865 insertions(+)
>   create mode 100644 tests/intel/xe_madvise.c
>