[LTP] [PATCH v2] getrusage03: mlock all address space for process calling consume_mb

[Li Wang]

It is trying to test without swap happen to guarantee less disturbing
for the ’->ru_maxrss‘ counting.

Therefore add mlockall() to prevent that memory address space
of the calling process from being paged to the swap area.

Due to that lock needs CAP_IPC_LOCK capability and child can not
inherit memory locks from parent, here add the definition and put
the mlockall() in consume_mb.

Signed-off-by: Li Wang <liwang@redhat.com>
---
 include/lapi/capability.h                         | 4 ++++
 testcases/kernel/syscalls/getrusage/getrusage03.c | 4 ++++
 testcases/kernel/syscalls/getrusage/getrusage03.h | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/include/lapi/capability.h b/include/lapi/capability.h
index 8cabd0f28..17ec107b1 100644
--- a/include/lapi/capability.h
+++ b/include/lapi/capability.h
@@ -24,6 +24,10 @@
 # define CAP_NET_RAW          13
 #endif
 
+#ifndef CAP_IPC_LOCK
+# define CAP_IPC_LOCK         14
+#endif
+
 #ifndef CAP_SYS_CHROOT
 # define CAP_SYS_CHROOT       18
 #endif
diff --git a/testcases/kernel/syscalls/getrusage/getrusage03.c b/testcases/kernel/syscalls/getrusage/getrusage03.c
index 201d258fa..43fab0605 100644
--- a/testcases/kernel/syscalls/getrusage/getrusage03.c
+++ b/testcases/kernel/syscalls/getrusage/getrusage03.c
@@ -193,4 +193,8 @@ static struct tst_test test = {
 	.setup = setup,
 	.test = run,
 	.tcnt = ARRAY_SIZE(testfunc_list),
+	.caps = (struct tst_cap []) {
+		TST_CAP(TST_CAP_REQ, CAP_IPC_LOCK),
+		{}
+	},
 };
diff --git a/testcases/kernel/syscalls/getrusage/getrusage03.h b/testcases/kernel/syscalls/getrusage/getrusage03.h
index f1bbe9be5..b28b9d4c3 100644
--- a/testcases/kernel/syscalls/getrusage/getrusage03.h
+++ b/testcases/kernel/syscalls/getrusage/getrusage03.h
@@ -16,6 +16,8 @@ static void consume_mb(int consume_nr)
 	size_t size;
 	unsigned long vmswap_size;
 
+	mlockall(MCL_CURRENT|MCL_FUTURE);
+
 	size = consume_nr * 1024 * 1024;
 	ptr = SAFE_MALLOC(size);
 	memset(ptr, 0, size);
-- 
2.31.1