diff options
Diffstat (limited to 'tools/testing/selftests/mm/hmm-tests.c')
| -rw-r--r-- | tools/testing/selftests/mm/hmm-tests.c | 919 |
1 files changed, 858 insertions, 61 deletions
diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index 15aadaf24a66..5a1525f72daa 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -25,6 +25,7 @@ #include <sys/stat.h> #include <sys/mman.h> #include <sys/ioctl.h> +#include <sys/time.h> /* @@ -50,6 +51,8 @@ enum { HMM_COHERENCE_DEVICE_TWO, }; +#define ONEKB (1 << 10) +#define ONEMEG (1 << 20) #define TWOMEG (1 << 21) #define HMM_BUFFER_SIZE (1024 << 12) #define HMM_PATH_MAX 64 @@ -207,8 +210,10 @@ static void hmm_buffer_free(struct hmm_buffer *buffer) if (buffer == NULL) return; - if (buffer->ptr) + if (buffer->ptr) { munmap(buffer->ptr, buffer->size); + buffer->ptr = NULL; + } free(buffer->mirror); free(buffer); } @@ -525,6 +530,8 @@ TEST_F(hmm, anon_write_prot) /* * Check that a device writing an anonymous private mapping * will copy-on-write if a child process inherits the mapping. + * + * Also verifies after fork() memory the device can be read by child. */ TEST_F(hmm, anon_write_child) { @@ -532,72 +539,101 @@ TEST_F(hmm, anon_write_child) unsigned long npages; unsigned long size; unsigned long i; + void *old_ptr; + void *map; int *ptr; pid_t pid; int child_fd; - int ret; - - npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; - ASSERT_NE(npages, 0); - size = npages << self->page_shift; - - buffer = malloc(sizeof(*buffer)); - ASSERT_NE(buffer, NULL); - - buffer->fd = -1; - buffer->size = size; - buffer->mirror = malloc(size); - ASSERT_NE(buffer->mirror, NULL); - - buffer->ptr = mmap(NULL, size, - PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, - buffer->fd, 0); - ASSERT_NE(buffer->ptr, MAP_FAILED); - - /* Initialize buffer->ptr so we can tell if it is written. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ptr[i] = i; - - /* Initialize data that the device will write to buffer->ptr. */ - for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) - ptr[i] = -i; + int ret, use_thp, migrate; + + for (migrate = 0; migrate < 2; ++migrate) { + for (use_thp = 0; use_thp < 2; ++use_thp) { + npages = ALIGN(use_thp ? TWOMEG : HMM_BUFFER_SIZE, + self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = size * 2; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + buffer->ptr = mmap(NULL, size * 2, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + old_ptr = buffer->ptr; + if (use_thp) { + map = (void *)ALIGN((uintptr_t)buffer->ptr, size); + ret = madvise(map, size, MADV_HUGEPAGE); + ASSERT_EQ(ret, 0); + buffer->ptr = map; + } + + /* Initialize buffer->ptr so we can tell if it is written. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = -i; + + if (migrate) { + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + } + + pid = fork(); + if (pid == -1) + ASSERT_EQ(pid, 0); + if (pid != 0) { + waitpid(pid, &ret, 0); + ASSERT_EQ(WIFEXITED(ret), 1); + + /* Check that the parent's buffer did not change. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); + continue; + } + + /* Check that we see the parent's values. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + if (!migrate) { + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + } + + /* The child process needs its own mirror to its own mm. */ + child_fd = hmm_open(0); + ASSERT_GE(child_fd, 0); + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); - pid = fork(); - if (pid == -1) - ASSERT_EQ(pid, 0); - if (pid != 0) { - waitpid(pid, &ret, 0); - ASSERT_EQ(WIFEXITED(ret), 1); + /* Check what the device wrote. */ + if (!migrate) { + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + } - /* Check that the parent's buffer did not change. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], i); - return; + close(child_fd); + exit(0); + } } - - /* Check that we see the parent's values. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], i); - for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], -i); - - /* The child process needs its own mirror to its own mm. */ - child_fd = hmm_open(0); - ASSERT_GE(child_fd, 0); - - /* Simulate a device writing system memory. */ - ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); - ASSERT_EQ(ret, 0); - ASSERT_EQ(buffer->cpages, npages); - ASSERT_EQ(buffer->faults, 1); - - /* Check what the device wrote. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], -i); - - close(child_fd); - exit(0); } /* @@ -2055,4 +2091,765 @@ 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 memory and fault back to sysmem after partially unmapping. + */ +TEST_F(hmm, migrate_partial_unmap_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size = TWOMEG; + unsigned long i; + void *old_ptr; + void *map; + int *ptr; + int ret, j, use_thp; + int offsets[] = { 0, 512 * ONEKB, ONEMEG }; + + for (use_thp = 0; use_thp < 2; ++use_thp) { + for (j = 0; j < ARRAY_SIZE(offsets); ++j) { + 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); + if (use_thp) + ret = madvise(map, size, MADV_HUGEPAGE); + else + ret = madvise(map, size, MADV_NOHUGEPAGE); + 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); + + munmap(buffer->ptr + offsets[j], ONEMEG); + + /* Fault pages back to system memory and check them. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + if (i * sizeof(int) < offsets[j] || + i * sizeof(int) >= offsets[j] + ONEMEG) + ASSERT_EQ(ptr[i], i); + + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); + } + } +} + +TEST_F(hmm, migrate_remap_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size = TWOMEG; + unsigned long i; + void *old_ptr, *new_ptr = NULL; + void *map; + int *ptr; + int ret, j, use_thp, dont_unmap, before; + int offsets[] = { 0, 512 * ONEKB, ONEMEG }; + + for (before = 0; before < 2; ++before) { + for (dont_unmap = 0; dont_unmap < 2; ++dont_unmap) { + for (use_thp = 0; use_thp < 2; ++use_thp) { + for (j = 0; j < ARRAY_SIZE(offsets); ++j) { + int flags = MREMAP_MAYMOVE | MREMAP_FIXED; + + if (dont_unmap) + flags |= MREMAP_DONTUNMAP; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = 8 * size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + memset(buffer->mirror, 0xFF, size); + + buffer->ptr = mmap(NULL, buffer->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); + if (use_thp) + ret = madvise(map, size, MADV_HUGEPAGE); + else + ret = madvise(map, size, MADV_NOHUGEPAGE); + ASSERT_EQ(ret, 0); + old_ptr = buffer->ptr; + munmap(map + size, size * 2); + buffer->ptr = map; + + /* Initialize buffer in system memory. */ + for (i = 0, ptr = buffer->ptr; + i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + if (before) { + new_ptr = mremap((void *)map, size, size, flags, + map + size + offsets[j]); + ASSERT_NE(new_ptr, MAP_FAILED); + buffer->ptr = new_ptr; + } + + /* 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); + + if (!before) { + new_ptr = mremap((void *)map, size, size, flags, + map + size + offsets[j]); + ASSERT_NE(new_ptr, MAP_FAILED); + buffer->ptr = new_ptr; + } + + /* 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); + + munmap(new_ptr, size); + 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); +} + +struct benchmark_results { + double sys_to_dev_time; + double dev_to_sys_time; + double throughput_s2d; + double throughput_d2s; +}; + +static double get_time_ms(void) +{ + struct timeval tv; + + gettimeofday(&tv, NULL); + return (tv.tv_sec * 1000.0) + (tv.tv_usec / 1000.0); +} + +static inline struct hmm_buffer *hmm_buffer_alloc(unsigned long size) +{ + struct hmm_buffer *buffer; + + buffer = malloc(sizeof(*buffer)); + + buffer->fd = -1; + buffer->size = size; + buffer->mirror = malloc(size); + memset(buffer->mirror, 0xFF, size); + return buffer; +} + +static void print_benchmark_results(const char *test_name, size_t buffer_size, + struct benchmark_results *thp, + struct benchmark_results *regular) +{ + double s2d_improvement = ((regular->sys_to_dev_time - thp->sys_to_dev_time) / + regular->sys_to_dev_time) * 100.0; + double d2s_improvement = ((regular->dev_to_sys_time - thp->dev_to_sys_time) / + regular->dev_to_sys_time) * 100.0; + double throughput_s2d_improvement = ((thp->throughput_s2d - regular->throughput_s2d) / + regular->throughput_s2d) * 100.0; + double throughput_d2s_improvement = ((thp->throughput_d2s - regular->throughput_d2s) / + regular->throughput_d2s) * 100.0; + + printf("\n=== %s (%.1f MB) ===\n", test_name, buffer_size / (1024.0 * 1024.0)); + printf(" | With THP | Without THP | Improvement\n"); + printf("---------------------------------------------------------------------\n"); + printf("Sys->Dev Migration | %.3f ms | %.3f ms | %.1f%%\n", + thp->sys_to_dev_time, regular->sys_to_dev_time, s2d_improvement); + printf("Dev->Sys Migration | %.3f ms | %.3f ms | %.1f%%\n", + thp->dev_to_sys_time, regular->dev_to_sys_time, d2s_improvement); + printf("S->D Throughput | %.2f GB/s | %.2f GB/s | %.1f%%\n", + thp->throughput_s2d, regular->throughput_s2d, throughput_s2d_improvement); + printf("D->S Throughput | %.2f GB/s | %.2f GB/s | %.1f%%\n", + thp->throughput_d2s, regular->throughput_d2s, throughput_d2s_improvement); +} + +/* + * Run a single migration benchmark + * fd: file descriptor for hmm device + * use_thp: whether to use THP + * buffer_size: size of buffer to allocate + * iterations: number of iterations + * results: where to store results + */ +static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_size, + int iterations, struct benchmark_results *results) +{ + struct hmm_buffer *buffer; + unsigned long npages = buffer_size / sysconf(_SC_PAGESIZE); + double start, end; + double s2d_total = 0, d2s_total = 0; + int ret, i; + int *ptr; + + buffer = hmm_buffer_alloc(buffer_size); + + /* Map memory */ + buffer->ptr = mmap(NULL, buffer_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (!buffer->ptr) + return -1; + + /* Apply THP hint if requested */ + if (use_thp) + ret = madvise(buffer->ptr, buffer_size, MADV_HUGEPAGE); + else + ret = madvise(buffer->ptr, buffer_size, MADV_NOHUGEPAGE); + + if (ret) + return ret; + + /* Initialize memory to make sure pages are allocated */ + ptr = (int *)buffer->ptr; + for (i = 0; i < buffer_size / sizeof(int); i++) + ptr[i] = i & 0xFF; + + /* Warmup iteration */ + ret = hmm_migrate_sys_to_dev(fd, buffer, npages); + if (ret) + return ret; + + ret = hmm_migrate_dev_to_sys(fd, buffer, npages); + if (ret) + return ret; + + /* Benchmark iterations */ + for (i = 0; i < iterations; i++) { + /* System to device migration */ + start = get_time_ms(); + + ret = hmm_migrate_sys_to_dev(fd, buffer, npages); + if (ret) + return ret; + + end = get_time_ms(); + s2d_total += (end - start); + + /* Device to system migration */ + start = get_time_ms(); + + ret = hmm_migrate_dev_to_sys(fd, buffer, npages); + if (ret) + return ret; + + end = get_time_ms(); + d2s_total += (end - start); + } + + /* Calculate average times and throughput */ + results->sys_to_dev_time = s2d_total / iterations; + results->dev_to_sys_time = d2s_total / iterations; + results->throughput_s2d = (buffer_size / (1024.0 * 1024.0 * 1024.0)) / + (results->sys_to_dev_time / 1000.0); + results->throughput_d2s = (buffer_size / (1024.0 * 1024.0 * 1024.0)) / + (results->dev_to_sys_time / 1000.0); + + /* Cleanup */ + hmm_buffer_free(buffer); + return 0; +} + +/* + * Benchmark THP migration with different buffer sizes + */ +TEST_F_TIMEOUT(hmm, benchmark_thp_migration, 120) +{ + struct benchmark_results thp_results, regular_results; + size_t thp_size = 2 * 1024 * 1024; /* 2MB - typical THP size */ + int iterations = 5; + + printf("\nHMM THP Migration Benchmark\n"); + printf("---------------------------\n"); + printf("System page size: %ld bytes\n", sysconf(_SC_PAGESIZE)); + + /* Test different buffer sizes */ + size_t test_sizes[] = { + thp_size / 4, /* 512KB - smaller than THP */ + thp_size / 2, /* 1MB - half THP */ + thp_size, /* 2MB - single THP */ + thp_size * 2, /* 4MB - two THPs */ + thp_size * 4, /* 8MB - four THPs */ + thp_size * 8, /* 16MB - eight THPs */ + thp_size * 128, /* 256MB - one twenty eight THPs */ + }; + + static const char *const test_names[] = { + "Small Buffer (512KB)", + "Half THP Size (1MB)", + "Single THP Size (2MB)", + "Two THP Size (4MB)", + "Four THP Size (8MB)", + "Eight THP Size (16MB)", + "One twenty eight THP Size (256MB)" + }; + + int num_tests = ARRAY_SIZE(test_sizes); + + /* Run all tests */ + for (int i = 0; i < num_tests; i++) { + /* Test with THP */ + ASSERT_EQ(run_migration_benchmark(self->fd, 1, test_sizes[i], + iterations, &thp_results), 0); + + /* Test without THP */ + ASSERT_EQ(run_migration_benchmark(self->fd, 0, test_sizes[i], + iterations, ®ular_results), 0); + + /* Print results */ + print_benchmark_results(test_names[i], test_sizes[i], + &thp_results, ®ular_results); + } +} TEST_HARNESS_MAIN |