Some MM selftests attempt to configure the amount of
HugeTLB pages of different sizes by writing to nr_hugepages.
PowerPC hash MMU pSeries systems advertise gigantic hugepage sizes
but do not support runtime allocation of such pages, writes
to the corresponding nr_hugepages file fail with -EINVAL.
This causes the test to bail out even though the failure is due
to a platform limitation rather than the
functionality being tested.
Treat -EINVAL from the sysfs write as a skipped configuration request
and continue running the test instead of failing.
Before patch:
-------------------------
running ./hugetlb-madvise
-------------------------
TAP version 13
1..1
[INFO] detected hugetlb page size: 16777216 KiB
[INFO] detected hugetlb page size: 16384 KiB
ok 1 MADV_DONTNEED and MADV_REMOVE on hugetlb
Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
Bail out! /sys/kernel/mm/hugepages/hugepages-16777216kB/nr_hugepages
write(0) failed: Invalid argument
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
[FAIL]
After patch:
-------------------------
running ./hugetlb-madvise
-------------------------
TAP version 13
1..1
[INFO] detected hugetlb page size: 16777216 KiB
[INFO] detected hugetlb page size: 16384 KiB
ok 1 MADV_DONTNEED and MADV_REMOVE on hugetlb
Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
/sys/kernel/mm/hugepages/hugepages-16777216kB/nr_hugepages
write(0) failed: Invalid argument
[PASS]
Fixes: 27477b28b74f ("selftests/mm: hugepage_settings: add APIs to get and set
nr_hugepages")
Signed-off-by: Sayali Patil <[email protected]>
---
.../testing/selftests/mm/hugepage_settings.c | 32 ++++++++++++++++++-
.../testing/selftests/mm/hugepage_settings.h | 1 +
2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/hugepage_settings.c
b/tools/testing/selftests/mm/hugepage_settings.c
index 2eab2110ac6a..ce38ae3da01a 100644
--- a/tools/testing/selftests/mm/hugepage_settings.c
+++ b/tools/testing/selftests/mm/hugepage_settings.c
@@ -422,6 +422,36 @@ static void hugetlb_sysfs_path(char *buf, size_t buflen,
size / 1024, attr);
}
+void hugetlb_write_num(const char *path, unsigned long num)
+{
+ int fd, saved_errno;
+ ssize_t numwritten;
+ char buf[21];
+
+ sprintf(buf, "%lu", num);
+
+ fd = open(path, O_WRONLY);
+ if (fd == -1)
+ ksft_exit_fail_msg("%s open failed: %s\n", path,
strerror(errno));
+
+ numwritten = write(fd, buf, strlen(buf));
+ saved_errno = errno;
+ close(fd);
+ errno = saved_errno;
+
+ /* Treat EINVAL as a skipped configuration (e.g., unsupported gigantic
pages) */
+ if (numwritten < 0 && errno == EINVAL) {
+ ksft_print_msg("%s write(%s) failed: %s\n", path, buf,
strerror(errno));
+ return;
+ }
+
+ if (numwritten < 0)
+ ksft_exit_fail_msg("%s write(%s) failed: %s\n", path, buf,
strerror(errno));
+ if (numwritten != strlen(buf))
+ ksft_exit_fail_msg("%s write(%s) is truncated, expected %zu
bytes, got %zd bytes\n",
+ path, buf, strlen(buf), numwritten);
+}
+
unsigned long hugetlb_nr_pages(unsigned long size)
{
char path[PATH_MAX];
@@ -437,7 +467,7 @@ void hugetlb_set_nr_pages(unsigned long size, unsigned long
nr)
hugetlb_sysfs_path(path, sizeof(path), size, "nr_hugepages");
- write_num(path, nr);
+ hugetlb_write_num(path, nr);
}
unsigned long hugetlb_free_pages(unsigned long size)
diff --git a/tools/testing/selftests/mm/hugepage_settings.h
b/tools/testing/selftests/mm/hugepage_settings.h
index 726c73c43c05..390fcc483b9e 100644
--- a/tools/testing/selftests/mm/hugepage_settings.h
+++ b/tools/testing/selftests/mm/hugepage_settings.h
@@ -95,6 +95,7 @@ bool thp_is_enabled(void);
int detect_hugetlb_page_sizes(unsigned long sizes[], int max);
unsigned long default_huge_page_size(void);
+void hugetlb_write_num(const char *path, unsigned long num);
unsigned long hugetlb_nr_pages(unsigned long size);
void hugetlb_set_nr_pages(unsigned long size, unsigned long nr);
unsigned long hugetlb_free_pages(unsigned long size);
--
2.52.0
