If HUGETLB is configured in the host kernel, then we can know the system
default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will
not see the information of hugetlb pages in file /proc/meminfo if it's not
configured. So add a helper to determine whether HUGETLB is configured and
then get the default page size by reading /proc/meminfo.
This helper can be useful when a program wants to use the default hugetlb
pages of the system and doesn't know the default page size.
Signed-off-by: Yanan Wang <wangyana...@huawei.com>
Reviewed-by: Andrew Jones <drjo...@redhat.com>
---
.../testing/selftests/kvm/include/test_util.h | 1 +
tools/testing/selftests/kvm/lib/test_util.c | 25 +++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/test_util.h
b/tools/testing/selftests/kvm/include/test_util.h
index ef24c76ba89a..e087174eefe5 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -80,6 +80,7 @@ struct vm_mem_backing_src_alias {
bool thp_configured(void);
size_t get_trans_hugepagesz(void);
+size_t get_def_hugetlb_pagesz(void);
void backing_src_help(void);
enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);
diff --git a/tools/testing/selftests/kvm/lib/test_util.c
b/tools/testing/selftests/kvm/lib/test_util.c
index efc1a7782de0..665724ccab97 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -146,6 +146,31 @@ size_t get_trans_hugepagesz(void)
return size;
}
+size_t get_def_hugetlb_pagesz(void)
+{
+ char buf[64];
+ const char *tag = "Hugepagesize:";
+ FILE *f;
+
+ f = fopen("/proc/meminfo", "r");
+ TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo");
+
+ while (fgets(buf, sizeof(buf), f) != NULL) {
+ if (strstr(buf, tag) == buf) {
+ fclose(f);
+ return strtoull(buf + strlen(tag), NULL, 10) << 10;
+ }
+ }
+
+ if (feof(f))
+ TEST_FAIL("HUGETLB is not configured in host kernel");
+ else
+ TEST_FAIL("Error in reading /proc/meminfo");
+
+ fclose(f);
+ return 0;
+}
+
void backing_src_help(void)
{
int i;
--
2.19.1
