Re: [PATCH i-g-t v7 3/9] tests/intel/xe_madvise: Add dontneed-before-mmap subtest

Sharma, Nishit
2026-04-10T07:11:01Z

On 4/9/2026 12:31 PM, Arvind Yadav wrote:
> This test validates that mmap() fails with -EBUSY when attempting to
> map a BO marked DONTNEED. The mmap offset ioctl succeeds (it just
> returns the pre-allocated offset); the purgeable check happens in
> xe_gem_object_mmap() at mmap() time.
>
> - DONTNEED BOs: return -EBUSY (temporary purgeable state, BO still
> has backing store but can be purged at any time)
> - Purged BOs: return -EINVAL (permanent, backing store discarded)
>
> v4:
> - Move unmap outside the block. (Pravalika)
> - Added proper resource cleanup before calling igt_skip(). (Nishit)
> - Added assertion for xe_bo_map. (Nishit)
>
> v5:
> - Add kernel capability check *_FLAG_HAS_PURGING_SUPPORT for
> purgeable support. (Jose)
> - Drop memory pressure trigger path; mark DONTNEED directly and
> assert -EBUSY from mmap offset ioctl; restore WILLNEED before
> cleanup.
>
> v6:
> - Support iGPU by using total system RAM as the pressure baseline
> instead of VRAM size (which is 0 on iGPU).
> - Raise overpressure from 25% to 50% of the baseline to ensure the
> kernel shrinker is forced to reclaim on systems with large free RAM.
> - The DONTNEED enforcement point is mmap() itself, not the
> DRM_IOCTL_XE_GEM_MMAP_OFFSET ioctl. Update the test to mark DONTNEED
> first, then verify DRM_IOCTL_XE_GEM_MMAP_OFFSET still succeeds, and
> finally verify that mmap() fails with -EBUSY
>
> v7:
> - Move unused functions: trigger_memory_pressure(), sigtrap and
> purgeable_mark_and_verify_purged. (Nishit)
>
> Cc: Nishit Sharma <nishit.sharma@intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> Cc: Pravalika Gurram <pravalika.gurram@intel.com>
> Signed-off-by: Arvind Yadav <arvind.yadav@intel.com>
> ---
> tests/intel/xe_madvise.c | 122 +++++++++++++++++++++++++++++++++++++++
> tests/meson.build | 1 +
> 2 files changed, 123 insertions(+)
> create mode 100644 tests/intel/xe_madvise.c
>
> diff --git a/tests/intel/xe_madvise.c b/tests/intel/xe_madvise.c
> new file mode 100644
> index 000000000..2c8c27fa9
> --- /dev/null
> +++ b/tests/intel/xe_madvise.c
> @@ -0,0 +1,122 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +/**
> + * TEST: Validate purgeable BO madvise functionality
> + * Category: Core
> + * Mega feature: General Core features
> + * Sub-category: Memory management tests
> + * Functionality: madvise, purgeable
> + */
> +
> +#include "igt.h"
> +#include "xe_drm.h"
> +
> +#include "xe/xe_ioctl.h"
> +#include "xe/xe_query.h"
> +
> +/* Purgeable test constants */
> +#define PURGEABLE_ADDR 0x1a0000
> +#define PURGEABLE_BO_SIZE 4096
> +
> +static bool xe_has_purgeable_support(int fd)
> +{
> + struct drm_xe_query_config *config = xe_config(fd);
> +
> + return config->info[DRM_XE_QUERY_CONFIG_FLAGS] &
> + DRM_XE_QUERY_CONFIG_FLAG_HAS_PURGING_SUPPORT;
> +}
> +
> +/**
> + * purgeable_setup_simple_bo - Setup VM and bind a single BO
> + * @fd: DRM file descriptor
> + * @vm: Output VM handle
> + * @bo: Output BO handle
> + * @addr: Virtual address to bind at
> + * @size: Size of the BO
> + * @use_scratch: Whether to use scratch page flag
> + *
> + * Helper to create VM, BO, and bind it at the specified address.
> + */
> +static void purgeable_setup_simple_bo(int fd, uint32_t *vm, uint32_t *bo,
> + uint64_t addr, size_t size, bool use_scratch)
> +{
> + struct drm_xe_sync sync = {
> + .type = DRM_XE_SYNC_TYPE_USER_FENCE,
> + .flags = DRM_XE_SYNC_FLAG_SIGNAL,
> + .timeline_value = 1,
> + };
> + uint64_t sync_val = 0;
> +
> + *vm = xe_vm_create(fd, use_scratch ? DRM_XE_VM_CREATE_FLAG_SCRATCH_PAGE : 0, 0);
> + *bo = xe_bo_create(fd, *vm, size, vram_if_possible(fd, 0),
> + DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
> +
> + sync.addr = to_user_pointer(&sync_val);
> + xe_vm_bind_async(fd, *vm, 0, *bo, 0, addr, size, &sync, 1);
> + xe_wait_ufence(fd, &sync_val, 1, 0, NSEC_PER_SEC);
> +}
> +
> +/**
> + * SUBTEST: dontneed-before-mmap
> + * Description: Mark BO as DONTNEED before mmap, verify mmap() fails with -EBUSY
> + * Test category: functionality test
> + */
> +static void test_dontneed_before_mmap(int fd)
> +{
> + uint32_t bo, vm;
> + uint64_t addr = PURGEABLE_ADDR;
> + size_t bo_size = PURGEABLE_BO_SIZE;
> + struct drm_xe_gem_mmap_offset mmo = {};
> + uint32_t retained;
> + void *ptr;
> +
> + purgeable_setup_simple_bo(fd, &vm, &bo, addr, bo_size, false);
> +
> + /* Mark BO as DONTNEED - new mmap operations must be blocked */
> + retained = xe_vm_madvise_purgeable(fd, vm, addr, bo_size,
> + DRM_XE_VMA_PURGEABLE_STATE_DONTNEED);
> + igt_assert_eq(retained, 1);
> +
> + /* Ioctl succeeds even for DONTNEED BO; blocking happens at mmap() time. */
> + mmo.handle = bo;
> + igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo), 0);
> +
> + /* mmap() on a DONTNEED BO must fail with EBUSY. */
> + ptr = mmap(NULL, bo_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, mmo.offset);
> + igt_assert_eq_u64((uint64_t)ptr, (uint64_t)MAP_FAILED);
> + igt_assert_eq(errno, EBUSY);
> +
> + /* Restore to WILLNEED before cleanup */
> + xe_vm_madvise_purgeable(fd, vm, addr, bo_size,
> + DRM_XE_VMA_PURGEABLE_STATE_WILLNEED);
> +
> + gem_close(fd, bo);
> + xe_vm_destroy(fd, vm);
> +}
> +
> +int igt_main()
> +{
> + struct drm_xe_engine_class_instance *hwe;
> + int fd;
> +
> + igt_fixture() {
> + fd = drm_open_driver(DRIVER_XE);
> + xe_device_get(fd);
> + igt_require_f(xe_has_purgeable_support(fd),
> + "Kernel does not support purgeable buffer objects\n");
> + }
> +
> + igt_subtest("dontneed-before-mmap")
> + xe_for_each_engine(fd, hwe) {
> + test_dontneed_before_mmap(fd);
> + break;
> + }
> +
> + igt_fixture() {
> + xe_device_put(fd);
> + drm_close_driver(fd);
> + }
> +}
> diff --git a/tests/meson.build b/tests/meson.build
> index cecb4a8ae..a6370b685 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -314,6 +314,7 @@ intel_xe_progs = [
> 'xe_huc_copy',
> 'xe_intel_bb',
> 'xe_live_ktest',
> + 'xe_madvise',
> 'xe_media_fill',
> 'xe_mmap',
> 'xe_module_load',

LGTM:

Reviewed-by: Nishit Sharma <nishit.sharma@intel.com>