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Diffstat (limited to 'tools/testing/selftests/vm/userfaultfd.c')
-rw-r--r--tools/testing/selftests/vm/userfaultfd.c134
1 files changed, 77 insertions, 57 deletions
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 7b8171e3128a..5d1db824f73a 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -34,18 +34,6 @@
* per-CPU threads 1 by triggering userfaults inside
* pthread_mutex_lock will also verify the atomicity of the memory
* transfer (UFFDIO_COPY).
- *
- * The program takes two parameters: the amounts of physical memory in
- * megabytes (MiB) of the area and the number of bounces to execute.
- *
- * # 100MiB 99999 bounces
- * ./userfaultfd 100 99999
- *
- * # 1GiB 99 bounces
- * ./userfaultfd 1000 99
- *
- * # 10MiB-~6GiB 999 bounces, continue forever unless an error triggers
- * while ./userfaultfd $[RANDOM % 6000 + 10] 999; do true; done
*/
#define _GNU_SOURCE
@@ -115,6 +103,30 @@ pthread_attr_t attr;
~(unsigned long)(sizeof(unsigned long long) \
- 1)))
+const char *examples =
+ "# Run anonymous memory test on 100MiB region with 99999 bounces:\n"
+ "./userfaultfd anon 100 99999\n\n"
+ "# Run share memory test on 1GiB region with 99 bounces:\n"
+ "./userfaultfd shmem 1000 99\n\n"
+ "# Run hugetlb memory test on 256MiB region with 50 bounces (using /dev/hugepages/hugefile):\n"
+ "./userfaultfd hugetlb 256 50 /dev/hugepages/hugefile\n\n"
+ "# Run the same hugetlb test but using shmem:\n"
+ "./userfaultfd hugetlb_shared 256 50 /dev/hugepages/hugefile\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";
+
+static void usage(void)
+{
+ fprintf(stderr, "\nUsage: ./userfaultfd <test type> <MiB> <bounces> "
+ "[hugetlbfs_file]\n\n");
+ fprintf(stderr, "Supported <test type>: anon, hugetlb, "
+ "hugetlb_shared, shmem\n\n");
+ fprintf(stderr, "Examples:\n\n");
+ fprintf(stderr, examples);
+ exit(1);
+}
+
static int anon_release_pages(char *rel_area)
{
int ret = 0;
@@ -439,6 +451,43 @@ static int copy_page(int ufd, unsigned long offset)
return __copy_page(ufd, offset, false);
}
+static int uffd_read_msg(int ufd, struct uffd_msg *msg)
+{
+ int ret = read(uffd, msg, sizeof(*msg));
+
+ if (ret != sizeof(*msg)) {
+ if (ret < 0) {
+ if (errno == EAGAIN)
+ return 1;
+ else
+ perror("blocking read error"), exit(1);
+ } else {
+ fprintf(stderr, "short read\n"), exit(1);
+ }
+ }
+
+ return 0;
+}
+
+/* Return 1 if page fault handled by us; otherwise 0 */
+static int uffd_handle_page_fault(struct uffd_msg *msg)
+{
+ unsigned long offset;
+
+ if (msg->event != UFFD_EVENT_PAGEFAULT)
+ fprintf(stderr, "unexpected msg event %u\n",
+ msg->event), exit(1);
+
+ if (bounces & BOUNCE_VERIFY &&
+ msg->arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WRITE)
+ fprintf(stderr, "unexpected write fault\n"), exit(1);
+
+ offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;
+ offset &= ~(page_size-1);
+
+ return copy_page(uffd, offset);
+}
+
static void *uffd_poll_thread(void *arg)
{
unsigned long cpu = (unsigned long) arg;
@@ -446,7 +495,6 @@ static void *uffd_poll_thread(void *arg)
struct uffd_msg msg;
struct uffdio_register uffd_reg;
int ret;
- unsigned long offset;
char tmp_chr;
unsigned long userfaults = 0;
@@ -470,25 +518,15 @@ static void *uffd_poll_thread(void *arg)
if (!(pollfd[0].revents & POLLIN))
fprintf(stderr, "pollfd[0].revents %d\n",
pollfd[0].revents), exit(1);
- ret = read(uffd, &msg, sizeof(msg));
- if (ret < 0) {
- if (errno == EAGAIN)
- continue;
- perror("nonblocking read error"), exit(1);
- }
+ if (uffd_read_msg(uffd, &msg))
+ continue;
switch (msg.event) {
default:
fprintf(stderr, "unexpected msg event %u\n",
msg.event), exit(1);
break;
case UFFD_EVENT_PAGEFAULT:
- if (msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WRITE)
- fprintf(stderr, "unexpected write fault\n"), exit(1);
- offset = (char *)(unsigned long)msg.arg.pagefault.address -
- area_dst;
- offset &= ~(page_size-1);
- if (copy_page(uffd, offset))
- userfaults++;
+ userfaults += uffd_handle_page_fault(&msg);
break;
case UFFD_EVENT_FORK:
close(uffd);
@@ -516,8 +554,6 @@ static void *uffd_read_thread(void *arg)
{
unsigned long *this_cpu_userfaults;
struct uffd_msg msg;
- unsigned long offset;
- int ret;
this_cpu_userfaults = (unsigned long *) arg;
*this_cpu_userfaults = 0;
@@ -526,24 +562,9 @@ static void *uffd_read_thread(void *arg)
/* from here cancellation is ok */
for (;;) {
- ret = read(uffd, &msg, sizeof(msg));
- if (ret != sizeof(msg)) {
- if (ret < 0)
- perror("blocking read error"), exit(1);
- else
- fprintf(stderr, "short read\n"), exit(1);
- }
- if (msg.event != UFFD_EVENT_PAGEFAULT)
- fprintf(stderr, "unexpected msg event %u\n",
- msg.event), exit(1);
- if (bounces & BOUNCE_VERIFY &&
- msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WRITE)
- fprintf(stderr, "unexpected write fault\n"), exit(1);
- offset = (char *)(unsigned long)msg.arg.pagefault.address -
- area_dst;
- offset &= ~(page_size-1);
- if (copy_page(uffd, offset))
- (*this_cpu_userfaults)++;
+ if (uffd_read_msg(uffd, &msg))
+ continue;
+ (*this_cpu_userfaults) += uffd_handle_page_fault(&msg);
}
return (void *)NULL;
}
@@ -605,6 +626,12 @@ static int stress(unsigned long *userfaults)
if (uffd_test_ops->release_pages(area_src))
return 1;
+
+ finished = 1;
+ for (cpu = 0; cpu < nr_cpus; cpu++)
+ if (pthread_join(locking_threads[cpu], NULL))
+ return 1;
+
for (cpu = 0; cpu < nr_cpus; cpu++) {
char c;
if (bounces & BOUNCE_POLL) {
@@ -622,11 +649,6 @@ static int stress(unsigned long *userfaults)
}
}
- finished = 1;
- for (cpu = 0; cpu < nr_cpus; cpu++)
- if (pthread_join(locking_threads[cpu], NULL))
- return 1;
-
return 0;
}
@@ -1272,8 +1294,7 @@ static void sigalrm(int sig)
int main(int argc, char **argv)
{
if (argc < 4)
- fprintf(stderr, "Usage: <test type> <MiB> <bounces> [hugetlbfs_file]\n"),
- exit(1);
+ usage();
if (signal(SIGALRM, sigalrm) == SIG_ERR)
fprintf(stderr, "failed to arm SIGALRM"), exit(1);
@@ -1286,20 +1307,19 @@ int main(int argc, char **argv)
nr_cpus;
if (!nr_pages_per_cpu) {
fprintf(stderr, "invalid MiB\n");
- fprintf(stderr, "Usage: <MiB> <bounces>\n"), exit(1);
+ usage();
}
bounces = atoi(argv[3]);
if (bounces <= 0) {
fprintf(stderr, "invalid bounces\n");
- fprintf(stderr, "Usage: <MiB> <bounces>\n"), exit(1);
+ usage();
}
nr_pages = nr_pages_per_cpu * nr_cpus;
if (test_type == TEST_HUGETLB) {
if (argc < 5)
- fprintf(stderr, "Usage: hugetlb <MiB> <bounces> <hugetlbfs_file>\n"),
- exit(1);
+ usage();
huge_fd = open(argv[4], O_CREAT | O_RDWR, 0755);
if (huge_fd < 0) {
fprintf(stderr, "Open of %s failed", argv[3]);
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-23 10:35:08 +0300