Re: [PATCH 17/29] selftests/mm: Drop global mem_fd in uffd tests

Mike Rapoport
2023-04-11T10:40:39Z

On Thu, Mar 30, 2023 at 12:08:06PM -0400, Peter Xu wrote:
> Drop it by creating the memfd dynamically in the tests.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> tools/testing/selftests/mm/uffd-common.c | 28 +++++++++++++++++++++++-
> tools/testing/selftests/mm/uffd-common.h | 2 +-
> tools/testing/selftests/mm/uffd-stress.c | 15 -------------
> 3 files changed, 28 insertions(+), 17 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
> index 3a9b5c1aca9d..a2b6e4957d0f 100644
> --- a/tools/testing/selftests/mm/uffd-common.c
> +++ b/tools/testing/selftests/mm/uffd-common.c
> @@ -12,12 +12,32 @@
> volatile bool test_uffdio_copy_eexist = true;
> unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size, hpage_size;
> char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap;
> -int mem_fd, uffd = -1, uffd_flags, finished, *pipefd, test_type;
> +int uffd = -1, uffd_flags, finished, *pipefd, test_type;
> bool map_shared, test_collapse, test_dev_userfaultfd;
> bool test_uffdio_wp = true, test_uffdio_minor = false;
> unsigned long long *count_verify;
> uffd_test_ops_t *uffd_test_ops;
>
> +static int uffd_mem_fd_create(off_t mem_size, bool hugetlb)
> +{
> + unsigned int memfd_flags = 0;
> + int mem_fd;
> +
> + if (hugetlb)
> + memfd_flags = MFD_HUGETLB;
> + mem_fd = memfd_create("uffd-test", memfd_flags);
> + if (mem_fd < 0)
> + err("memfd_create");
> + if (ftruncate(mem_fd, mem_size))
> + err("ftruncate");
> + if (fallocate(mem_fd,
> + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
> + mem_size))
> + err("fallocate");
> +
> + return mem_fd;
> +}
> +
> static void anon_release_pages(char *rel_area)
> {
> if (madvise(rel_area, nr_pages * page_size, MADV_DONTNEED))
> @@ -51,6 +71,7 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
> off_t offset = is_src ? 0 : size;
> void *area_alias = NULL;
> char **alloc_area_alias;
> + int mem_fd = uffd_mem_fd_create(size * 2, true);
>
> *alloc_area = mmap(NULL, size, PROT_READ | PROT_WRITE,
> (map_shared ? MAP_SHARED : MAP_PRIVATE) |
> @@ -73,6 +94,8 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
> }
> if (area_alias)
> *alloc_area_alias = area_alias;
> +
> + close(mem_fd);
> }
>
> static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset)
> @@ -95,6 +118,7 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
> size_t bytes = nr_pages * page_size;
> unsigned long offset = is_src ? 0 : bytes;
> char *p = NULL, *p_alias = NULL;
> + int mem_fd = uffd_mem_fd_create(bytes * 2, false);
>
> if (test_collapse) {
> p = BASE_PMD_ADDR;
> @@ -124,6 +148,8 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
> area_src_alias = area_alias;
> else
> area_dst_alias = area_alias;
> +
> + close(mem_fd);
> }
>
> static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
> diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
> index 11f770391bd9..0dfab7057295 100644
> --- a/tools/testing/selftests/mm/uffd-common.h
> +++ b/tools/testing/selftests/mm/uffd-common.h
> @@ -87,7 +87,7 @@ typedef struct uffd_test_ops uffd_test_ops_t;
>
> extern unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size, hpage_size;
> extern char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap;
> -extern int mem_fd, uffd, uffd_flags, finished, *pipefd, test_type;
> +extern int uffd, uffd_flags, finished, *pipefd, test_type;
> extern bool map_shared, test_collapse, test_dev_userfaultfd;
> extern bool test_uffdio_wp, test_uffdio_minor;
> extern unsigned long long *count_verify;
> diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
> index e6d39a755082..4eca1a0276c2 100644
> --- a/tools/testing/selftests/mm/uffd-stress.c
> +++ b/tools/testing/selftests/mm/uffd-stress.c
> @@ -1090,21 +1090,6 @@ int main(int argc, char **argv)
> }
> nr_pages = nr_pages_per_cpu * nr_cpus;
>
> - if (test_type == TEST_SHMEM || test_type == TEST_HUGETLB) {
> - unsigned int memfd_flags = 0;
> -
> - if (test_type == TEST_HUGETLB)
> - memfd_flags = MFD_HUGETLB;
> - mem_fd = memfd_create(argv[0], memfd_flags);
> - if (mem_fd < 0)
> - err("memfd_create");
> - if (ftruncate(mem_fd, nr_pages * page_size * 2))
> - err("ftruncate");
> - if (fallocate(mem_fd,
> - FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
> - nr_pages * page_size * 2))
> - err("fallocate");
> - }
> printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n",
> nr_pages, nr_pages_per_cpu);
> return userfaultfd_stress();
> --
> 2.39.1
>

--
Sincerely yours,
Mike.