[PATCH v18 11/24] selftests: vm: pkeys: Use the correct huge page size

Sandipan Das
2020-01-30T06:37:52Z

The huge page size can vary across architectures. This will
ensure that the correct huge page size is used when accessing
the hugetlb controls under sysfs. Instead of using a hardcoded
page size (i.e. 2MB), this now uses the HPAGE_SIZE macro which
is arch-specific.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/vm/protection_keys.c | 23 ++++++++++++++------
1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 9cc82b65f828..535e464e27e9 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -739,12 +739,15 @@ void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
}

int hugetlb_setup_ok;
+#define SYSFS_FMT_NR_HUGE_PAGES "/sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages"
#define GET_NR_HUGE_PAGES 10
void setup_hugetlbfs(void)
{
int err;
int fd;
- char buf[] = "123";
+ char buf[256];
+ long hpagesz_kb;
+ long hpagesz_mb;

if (geteuid() != 0) {
fprintf(stderr, "WARNING: not run as root, can not do hugetlb test\n");
@@ -755,11 +758,16 @@ void setup_hugetlbfs(void)

/*
* Now go make sure that we got the pages and that they
- * are 2M pages. Someone might have made 1G the default.
+ * are PMD-level pages. Someone might have made PUD-level
+ * pages the default.
*/
- fd = open("/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages", O_RDONLY);
+ hpagesz_kb = HPAGE_SIZE / 1024;
+ hpagesz_mb = hpagesz_kb / 1024;
+ sprintf(buf, SYSFS_FMT_NR_HUGE_PAGES, hpagesz_kb);
+ fd = open(buf, O_RDONLY);
if (fd < 0) {
- perror("opening sysfs 2M hugetlb config");
+ fprintf(stderr, "opening sysfs %ldM hugetlb config: %s\n",
+ hpagesz_mb, strerror(errno));
return;
}

@@ -767,13 +775,14 @@ void setup_hugetlbfs(void)
err = read(fd, buf, sizeof(buf)-1);
close(fd);
if (err <= 0) {
- perror("reading sysfs 2M hugetlb config");
+ fprintf(stderr, "reading sysfs %ldM hugetlb config: %s\n",
+ hpagesz_mb, strerror(errno));
return;
}

if (atoi(buf) != GET_NR_HUGE_PAGES) {
- fprintf(stderr, "could not confirm 2M pages, got: '%s' expected %d\n",
- buf, GET_NR_HUGE_PAGES);
+ fprintf(stderr, "could not confirm %ldM pages, got: '%s' expected %d\n",
+ hpagesz_mb, buf, GET_NR_HUGE_PAGES);
return;
}

--
2.17.1