+ selftests-vm-use-memfd-for-uffd-hugetlb-tests.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/vm: use memfd for uffd hugetlb tests
has been added to the -mm mm-unstable branch.  Its filename is
     selftests-vm-use-memfd-for-uffd-hugetlb-tests.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-vm-use-memfd-for-uffd-hugetlb-tests.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Peter Xu <peterx@redhat.com>
Subject: selftests/vm: use memfd for uffd hugetlb tests
Date: Fri, 14 Oct 2022 10:39:18 -0400

Patch series "selftests/vm: Drop hugetlb mntpoint in run_vmtests.sh", v2.


This patch (of 4):

We already used memfd for shmem test, move it forward with hugetlb too so
that we don't need user to specify the hugetlb file path explicitly when
running hugetlb shared tests.

Link: https://lkml.kernel.org/r/20221014143921.93887-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20221014143921.93887-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/vm/userfaultfd.c |   62 +++++++--------------
 1 file changed, 21 insertions(+), 41 deletions(-)

--- a/tools/testing/selftests/vm/userfaultfd.c~selftests-vm-use-memfd-for-uffd-hugetlb-tests
+++ a/tools/testing/selftests/vm/userfaultfd.c
@@ -93,10 +93,8 @@ static volatile bool test_uffdio_zeropag
 static bool test_uffdio_wp = true;
 /* Whether to test uffd minor faults */
 static bool test_uffdio_minor = false;
-
 static bool map_shared;
-static int shm_fd;
-static int huge_fd;
+static int mem_fd;
 static unsigned long long *count_verify;
 static int uffd = -1;
 static int uffd_flags, finished, *pipefd;
@@ -143,7 +141,7 @@ const char *examples =
     "# Run hugetlb memory test on 256MiB region with 50 bounces:\n"
     "./userfaultfd hugetlb 256 50\n\n"
     "# Run the same hugetlb test but using shared file:\n"
-    "./userfaultfd hugetlb_shared 256 50 /dev/hugepages/hugefile\n\n"
+    "./userfaultfd hugetlb_shared 256 50\n\n"
     "# 10MiB-~6GiB 999 bounces anonymous test, "
     "continue forever unless an error triggers\n"
     "while ./userfaultfd anon $[RANDOM % 6000 + 10] 999; do true; done\n\n";
@@ -260,35 +258,21 @@ static void hugetlb_release_pages(char *
 
 static void hugetlb_allocate_area(void **alloc_area, bool is_src)
 {
+	off_t size = nr_pages * page_size;
+	off_t offset = is_src ? 0 : size;
 	void *area_alias = NULL;
 	char **alloc_area_alias;
 
-	if (!map_shared)
-		*alloc_area = mmap(NULL,
-			nr_pages * page_size,
-			PROT_READ | PROT_WRITE,
-			MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB |
-				(is_src ? 0 : MAP_NORESERVE),
-			-1,
-			0);
-	else
-		*alloc_area = mmap(NULL,
-			nr_pages * page_size,
-			PROT_READ | PROT_WRITE,
-			MAP_SHARED |
-				(is_src ? 0 : MAP_NORESERVE),
-			huge_fd,
-			is_src ? 0 : nr_pages * page_size);
+	*alloc_area = mmap(NULL, size, PROT_READ | PROT_WRITE,
+			   (map_shared ? MAP_SHARED : MAP_PRIVATE) |
+			   (is_src ? 0 : MAP_NORESERVE),
+			   mem_fd, offset);
 	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,
-			huge_fd,
-			is_src ? 0 : nr_pages * page_size);
+		area_alias = mmap(NULL, size, PROT_READ | PROT_WRITE,
+				  MAP_SHARED, mem_fd, offset);
 		if (area_alias == MAP_FAILED)
 			err("mmap of hugetlb file alias failed");
 	}
@@ -334,14 +318,14 @@ static void shmem_allocate_area(void **a
 	}
 
 	*alloc_area = mmap(p, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
-			   shm_fd, offset);
+			   mem_fd, offset);
 	if (*alloc_area == MAP_FAILED)
 		err("mmap of memfd failed");
 	if (test_collapse && *alloc_area != p)
 		err("mmap of memfd failed at %p", p);
 
 	area_alias = mmap(p_alias, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
-			  shm_fd, offset);
+			  mem_fd, offset);
 	if (area_alias == MAP_FAILED)
 		err("mmap of memfd alias failed");
 	if (test_collapse && area_alias != p_alias)
@@ -1841,21 +1825,17 @@ int main(int argc, char **argv)
 	}
 	nr_pages = nr_pages_per_cpu * nr_cpus;
 
-	if (test_type == TEST_HUGETLB && map_shared) {
-		if (argc < 5)
-			usage();
-		huge_fd = open(argv[4], O_CREAT | O_RDWR, 0755);
-		if (huge_fd < 0)
-			err("Open of %s failed", argv[4]);
-		if (ftruncate(huge_fd, 0))
-			err("ftruncate %s to size 0 failed", argv[4]);
-	} else if (test_type == TEST_SHMEM) {
-		shm_fd = memfd_create(argv[0], 0);
-		if (shm_fd < 0)
+	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(shm_fd, nr_pages * page_size * 2))
+		if (ftruncate(mem_fd, nr_pages * page_size * 2))
 			err("ftruncate");
-		if (fallocate(shm_fd,
+		if (fallocate(mem_fd,
 			      FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
 			      nr_pages * page_size * 2))
 			err("fallocate");
_

Patches currently in -mm which might be from peterx@redhat.com are

selftests-vm-use-memfd-for-uffd-hugetlb-tests.patch
selftests-vm-use-memfd-for-hugetlb-madvise-test.patch
selftests-vm-use-memfd-for-hugepage-mremap-test.patch
selftests-vm-drop-mnt-point-for-hugetlb-in-run_vmtestssh.patch