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authorMike Kravetz <mike.kravetz@oracle.com>2022-01-14 14:08:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-15 16:30:30 +0200
commit692b55815cf970eb4ce428f48f2c94d1800acc4b (patch)
treeebd404c723c9e9c27987f5f025f9f3af3044e029 /tools
parentfab51505480058dcb63d973515c748fa6c437cab (diff)
downloadlinux-692b55815cf970eb4ce428f48f2c94d1800acc4b.tar.bz2
userfaultfd/selftests: clean up hugetlb allocation code
The message for commit f5c73297181c ("userfaultfd/selftests: fix hugetlb area allocations") says there is no need to create a hugetlb file in the non-shared testing case. However, the commit did not actually change the code to prevent creation of the file. While it is technically true that there is no need to create and use a hugetlb file in the case of non-shared-testing, it is useful. This is because 'hole punching' of a hugetlb file has the potentially incorrect side effect of also removing pages from private mappings. The userfaultfd test relies on this side effect for removing pages from the destination buffer during rounds of stress testing. Remove the incomplete code that was added to deal with no hugetlb file. Just keep the code that prevents reserves from being created for the destination area. Link: https://lkml.kernel.org/r/20220104021729.111006-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/vm/userfaultfd.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index c9eddd25ba17..d3fd24f9fae8 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -87,7 +87,7 @@ static bool test_uffdio_minor = false;
static bool map_shared;
static int shm_fd;
-static int huge_fd = -1; /* only used for hugetlb_shared test */
+static int huge_fd;
static char *huge_fd_off0;
static unsigned long long *count_verify;
static int uffd = -1;
@@ -223,9 +223,6 @@ static void noop_alias_mapping(__u64 *start, size_t len, unsigned long offset)
static void hugetlb_release_pages(char *rel_area)
{
- if (huge_fd == -1)
- return;
-
if (fallocate(huge_fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
rel_area == huge_fd_off0 ? 0 : nr_pages * page_size,
nr_pages * page_size))
@@ -238,17 +235,17 @@ static void hugetlb_allocate_area(void **alloc_area)
char **alloc_area_alias;
*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
- map_shared ? MAP_SHARED :
- MAP_PRIVATE | MAP_HUGETLB |
+ (map_shared ? MAP_SHARED : MAP_PRIVATE) |
+ MAP_HUGETLB |
(*alloc_area == area_src ? 0 : MAP_NORESERVE),
- huge_fd,
- *alloc_area == area_src ? 0 : nr_pages * page_size);
+ huge_fd, *alloc_area == area_src ? 0 :
+ nr_pages * page_size);
if (*alloc_area == MAP_FAILED)
err("mmap of hugetlbfs file failed");
if (map_shared) {
area_alias = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
- MAP_SHARED,
+ MAP_SHARED | MAP_HUGETLB,
huge_fd, *alloc_area == area_src ? 0 :
nr_pages * page_size);
if (area_alias == MAP_FAILED)