[PATCH i-g-t v6 3/9] tests/intel/xe_madvise: Add dontneed-before-mmap subtest

Arvind Yadav
2026-03-25T12:44:56Z

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

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 | 233 +++++++++++++++++++++++++++++++++++++++
tests/meson.build | 1 +
2 files changed, 234 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..de4a6e34c
--- /dev/null
+++ b/tests/intel/xe_madvise.c
@@ -0,0 +1,233 @@
+// 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"
+
+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 test constants */
+#define PURGEABLE_ADDR 0x1a0000
+#define PURGEABLE_BO_SIZE 4096
+
+/**
+ * trigger_memory_pressure - Fill VRAM/RAM + 50% to force purgeable reclaim
+ * @fd: DRM file descriptor
+ * @vm: VM handle (unused, kept for API compatibility)
+ *
+ * Allocates BOs in a temporary VM until memory is overcommitted by 50%,
+ * forcing the kernel to purge DONTNEED-marked BOs.
+ */
+static void trigger_memory_pressure(int fd, uint32_t vm)
+{
+ uint64_t vram_size, mem_size, overpressure;
+ const uint64_t chunk = 8ull << 20; /* 8 MiB */
+ int max_objs, n = 0;
+ uint32_t *handles;
+ uint64_t total;
+ void *p;
+ uint32_t handle, temp_vm;
+
+ /* Use a separate VM so pressure BOs don't affect the test VM */
+ temp_vm = xe_vm_create(fd, 0, 0);
+
+ vram_size = xe_visible_vram_size(fd, 0);
+ if (vram_size > 0) {
+ /* dGPU: pressure VRAM to trigger purgeable reclaim */
+ mem_size = vram_size;
+ } else {
+ /*
+ * iGPU: purgeable BOs reside in system memory. Use *total*
+ * RAM (not just available) as the baseline so that we always
+ * over-commit regardless of how much is already in use.
+ */
+ mem_size = igt_get_total_ram_mb() << 20;
+ }
+
+ /* Scale overpressure to 50% of memory, minimum 64MB */
+ overpressure = mem_size / 2;
+ if (overpressure < (64 << 20))
+ overpressure = 64 << 20;
+
+ max_objs = (mem_size + overpressure) / chunk + 1;
+ handles = malloc(max_objs * sizeof(*handles));
+ igt_assert(handles);
+
+ total = 0;
+ while (total < mem_size + overpressure && n < max_objs) {
+ uint32_t err;
+
+ err = __xe_bo_create(fd, temp_vm, chunk,
+ vram_if_possible(fd, 0),
+ DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ NULL, &handle);
+ if (err) /* Out of memory — sufficient pressure achieved */
+ break;
+
+ handles[n++] = handle;
+ total += chunk;
+
+ p = xe_bo_map(fd, handle, chunk);
+ igt_assert(p != MAP_FAILED);
+
+ /* Fault in all pages so they actually consume memory */
+ memset(p, 0xCD, chunk);
+ munmap(p, chunk);
+ }
+
+ /* Allow shrinker time to process pressure */
+ usleep(100000);
+
+ for (int i = 0; i < n; i++)
+ gem_close(fd, handles[i]);
+
+ free(handles);
+
+ xe_vm_destroy(fd, temp_vm);
+}
+
+static jmp_buf jmp;
+
+__noreturn static void sigtrap(int sig)
+{
+ siglongjmp(jmp, sig);
+}
+
+/**
+ * purgeable_mark_and_verify_purged - Mark DONTNEED, pressure, check purged
+ * @fd: DRM file descriptor
+ * @vm: VM handle
+ * @addr: Virtual address of the BO
+ * @size: Size of the BO
+ *
+ * Returns true if the BO was purged under memory pressure.
+ */
+static bool purgeable_mark_and_verify_purged(int fd, uint32_t vm, uint64_t addr, size_t size)
+{
+ uint32_t retained;
+
+ /* Mark as DONTNEED */
+ retained = xe_vm_madvise_purgeable(fd, vm, addr, size,
+ DRM_XE_VMA_PURGEABLE_STATE_DONTNEED);
+ if (retained != 1)
+ return false;
+
+ /* Trigger memory pressure */
+ trigger_memory_pressure(fd, vm);
+
+ /* Verify purged */
+ retained = xe_vm_madvise_purgeable(fd, vm, addr, size,
+ DRM_XE_VMA_PURGEABLE_STATE_WILLNEED);
+ return retained == 0;
+}
+
+/**
+ * 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',
--
2.43.0