From: Balbir Singh <balbirs@nvidia.com>
To: linux-mm@kvack.org
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Balbir Singh <balbirs@nvidia.com>
Subject: [v1 10/12] selftests/mm/hmm-tests: new tests for zone device THP migration
Date: Fri, 4 Jul 2025 08:27:57 +1000 [thread overview]
Message-ID: <20250703222759.1943776-11-balbirs@nvidia.com> (raw)
In-Reply-To: <20250703222759.1943776-1-balbirs@nvidia.com>
Add new tests for migrating anon THP pages, including anon_huge,
anon_huge_zero and error cases involving forced splitting of pages
during migration.
Signed-off-by: Balbir Singh <balbirs@nvidia.com>
---
tools/testing/selftests/mm/hmm-tests.c | 410 +++++++++++++++++++++++++
1 file changed, 410 insertions(+)
diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c
index 141bf63cbe05..da3322a1282c 100644
--- a/tools/testing/selftests/mm/hmm-tests.c
+++ b/tools/testing/selftests/mm/hmm-tests.c
@@ -2056,4 +2056,414 @@ TEST_F(hmm, hmm_cow_in_device)
hmm_buffer_free(buffer);
}
+
+/*
+ * Migrate private anonymous huge empty page.
+ */
+TEST_F(hmm, migrate_anon_huge_empty)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, size);
+
+ buffer->ptr = mmap(NULL, 2 * size,
+ PROT_READ,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)buffer->ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ old_ptr = buffer->ptr;
+ buffer->ptr = map;
+
+ /* Migrate memory to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], 0);
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Migrate private anonymous huge zero page.
+ */
+TEST_F(hmm, migrate_anon_huge_zero)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+ int val;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, size);
+
+ buffer->ptr = mmap(NULL, 2 * size,
+ PROT_READ,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)buffer->ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ old_ptr = buffer->ptr;
+ buffer->ptr = map;
+
+ /* Initialize a read-only zero huge page. */
+ val = *(int *)buffer->ptr;
+ ASSERT_EQ(val, 0);
+
+ /* Migrate memory to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], 0);
+
+ /* Fault pages back to system memory and check them. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) {
+ ASSERT_EQ(ptr[i], 0);
+ /* If it asserts once, it probably will 500,000 times */
+ if (ptr[i] != 0)
+ break;
+ }
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Migrate private anonymous huge page and free.
+ */
+TEST_F(hmm, migrate_anon_huge_free)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, size);
+
+ buffer->ptr = mmap(NULL, 2 * size,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)buffer->ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ old_ptr = buffer->ptr;
+ buffer->ptr = map;
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate memory to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
+
+ /* Try freeing it. */
+ ret = madvise(map, size, MADV_FREE);
+ ASSERT_EQ(ret, 0);
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Migrate private anonymous huge page and fault back to sysmem.
+ */
+TEST_F(hmm, migrate_anon_huge_fault)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, size);
+
+ buffer->ptr = mmap(NULL, 2 * size,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)buffer->ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ old_ptr = buffer->ptr;
+ buffer->ptr = map;
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate memory to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
+
+ /* Fault pages back to system memory and check them. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Migrate private anonymous huge page with allocation errors.
+ */
+TEST_F(hmm, migrate_anon_huge_err)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(2 * size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, 2 * size);
+
+ old_ptr = mmap(NULL, 2 * size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, buffer->fd, 0);
+ ASSERT_NE(old_ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)old_ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ buffer->ptr = map;
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate memory to device but force a THP allocation error. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_FLAGS, buffer,
+ HMM_DMIRROR_FLAG_FAIL_ALLOC);
+ ASSERT_EQ(ret, 0);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) {
+ ASSERT_EQ(ptr[i], i);
+ if (ptr[i] != i)
+ break;
+ }
+
+ /* Try faulting back a single (PAGE_SIZE) page. */
+ ptr = buffer->ptr;
+ ASSERT_EQ(ptr[2048], 2048);
+
+ /* unmap and remap the region to reset things. */
+ ret = munmap(old_ptr, 2 * size);
+ ASSERT_EQ(ret, 0);
+ old_ptr = mmap(NULL, 2 * size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, buffer->fd, 0);
+ ASSERT_NE(old_ptr, MAP_FAILED);
+ map = (void *)ALIGN((uintptr_t)old_ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ buffer->ptr = map;
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate THP to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /*
+ * Force an allocation error when faulting back a THP resident in the
+ * device.
+ */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_FLAGS, buffer,
+ HMM_DMIRROR_FLAG_FAIL_ALLOC);
+ ASSERT_EQ(ret, 0);
+
+ ret = hmm_migrate_dev_to_sys(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ptr = buffer->ptr;
+ ASSERT_EQ(ptr[2048], 2048);
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Migrate private anonymous huge zero page with allocation errors.
+ */
+TEST_F(hmm, migrate_anon_huge_zero_err)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ void *old_ptr;
+ void *map;
+ int *ptr;
+ int ret;
+
+ size = TWOMEG;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = 2 * size;
+ buffer->mirror = malloc(2 * size);
+ ASSERT_NE(buffer->mirror, NULL);
+ memset(buffer->mirror, 0xFF, 2 * size);
+
+ old_ptr = mmap(NULL, 2 * size, PROT_READ,
+ MAP_PRIVATE | MAP_ANONYMOUS, buffer->fd, 0);
+ ASSERT_NE(old_ptr, MAP_FAILED);
+
+ npages = size >> self->page_shift;
+ map = (void *)ALIGN((uintptr_t)old_ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ buffer->ptr = map;
+
+ /* Migrate memory to device but force a THP allocation error. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_FLAGS, buffer,
+ HMM_DMIRROR_FLAG_FAIL_ALLOC);
+ ASSERT_EQ(ret, 0);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], 0);
+
+ /* Try faulting back a single (PAGE_SIZE) page. */
+ ptr = buffer->ptr;
+ ASSERT_EQ(ptr[2048], 0);
+
+ /* unmap and remap the region to reset things. */
+ ret = munmap(old_ptr, 2 * size);
+ ASSERT_EQ(ret, 0);
+ old_ptr = mmap(NULL, 2 * size, PROT_READ,
+ MAP_PRIVATE | MAP_ANONYMOUS, buffer->fd, 0);
+ ASSERT_NE(old_ptr, MAP_FAILED);
+ map = (void *)ALIGN((uintptr_t)old_ptr, size);
+ ret = madvise(map, size, MADV_HUGEPAGE);
+ ASSERT_EQ(ret, 0);
+ buffer->ptr = map;
+
+ /* Initialize buffer in system memory (zero THP page). */
+ ret = ptr[0];
+ ASSERT_EQ(ret, 0);
+
+ /* Migrate memory to device but force a THP allocation error. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_FLAGS, buffer,
+ HMM_DMIRROR_FLAG_FAIL_ALLOC);
+ ASSERT_EQ(ret, 0);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ /* Fault the device memory back and check it. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], 0);
+
+ buffer->ptr = old_ptr;
+ hmm_buffer_free(buffer);
+}
TEST_HARNESS_MAIN
--
2.49.0
next prev parent reply other threads:[~2025-07-03 22:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-03 22:27 [v1 00/12] THP support for zone device page migration Balbir Singh
2025-07-03 22:27 ` [v1 01/12] mm/zone_device: support large zone device private folios Balbir Singh
2025-07-03 22:27 ` [v1 02/12] mm/migrate_device: flags for selecting device private THP pages Balbir Singh
2025-07-03 22:27 ` [v1 03/12] mm/thp: zone_device awareness in THP handling code Balbir Singh
2025-07-03 22:27 ` [v1 04/12] mm/migrate_device: THP migration of zone device pages Balbir Singh
2025-07-03 22:27 ` [v1 05/12] mm/memory/fault: add support for zone device THP fault handling Balbir Singh
2025-07-03 22:27 ` [v1 06/12] lib/test_hmm: test cases and support for zone device private THP Balbir Singh
2025-07-03 22:27 ` [v1 07/12] mm/memremap: add folio_split support Balbir Singh
2025-07-03 22:27 ` [v1 08/12] mm/thp: add split during migration support Balbir Singh
2025-07-03 22:27 ` [v1 09/12] lib/test_hmm: add test case for split pages Balbir Singh
2025-07-03 22:27 ` Balbir Singh [this message]
2025-07-03 22:27 ` [v1 11/12] gpu/drm/nouveau: add THP migration support Balbir Singh
2025-07-03 22:27 ` [v1 12/12] selftests/mm/hmm-tests: new throughput tests including THP Balbir Singh
2025-07-03 23:00 ` [v1 00/12] THP support for zone device page migration Zi Yan
2025-07-03 23:06 ` Balbir Singh
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