From: Filippo Storniolo <fstornio@redhat.com>
To: ltp@lists.linux.it
Cc: Filippo Storniolo <fstornio@redhat.com>
Subject: [LTP] [PATCH] syscalls/mlock05: add mlock test for locking and pre-faulting of memory
Date: Fri, 26 Apr 2024 15:48:02 +0200 [thread overview]
Message-ID: <20240426134802.2607150-1-fstornio@redhat.com> (raw)
check VmRSS and VmLck variables from /proc/$pid/status.
VmRSS size should at least as big as the memory allocation.
VmLck size should be equal to the size of the memory allocation.
Co-developed-by: Dennis Brendel <dbrendel@redhat.com>
Signed-off-by: Filippo Storniolo <fstornio@redhat.com>
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/mlock/.gitignore | 1 +
testcases/kernel/syscalls/mlock/mlock05.c | 69 ++++++++++++++++++++++
3 files changed, 71 insertions(+)
create mode 100644 testcases/kernel/syscalls/mlock/mlock05.c
diff --git a/runtest/syscalls b/runtest/syscalls
index 252123d8b..05a52fc8f 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -781,6 +781,7 @@ mlock01 mlock01
mlock02 mlock02
mlock03 mlock03 -i 20
mlock04 mlock04
+mlock05 mlock05
mlock201 mlock201
mlock202 mlock202
diff --git a/testcases/kernel/syscalls/mlock/.gitignore b/testcases/kernel/syscalls/mlock/.gitignore
index 306574bbc..1872229b8 100644
--- a/testcases/kernel/syscalls/mlock/.gitignore
+++ b/testcases/kernel/syscalls/mlock/.gitignore
@@ -2,3 +2,4 @@
/mlock02
/mlock03
/mlock04
+/mlock05
diff --git a/testcases/kernel/syscalls/mlock/mlock05.c b/testcases/kernel/syscalls/mlock/mlock05.c
new file mode 100644
index 000000000..e67cd1e03
--- /dev/null
+++ b/testcases/kernel/syscalls/mlock/mlock05.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright Red Hat
+ * Author: Filippo Storniolo <fstornio@redhat.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify mlock() causes pre-faulting of PTEs and prevent memory to be swapped out.
+ *
+ * Checks the variables VmRSS and VmLck in /proc/$pid/status after the
+ * mlock syscall:
+ * - VmRSS size should be at least as big as the memory allocation
+ * - VmLck size should be equal to the size of the memory allocation
+ */
+
+#include "tst_test.h"
+
+#define MMAPLEN (1UL<<20)
+
+static void verify_mlock(void)
+{
+ unsigned long VmRSS_before;
+ unsigned long VmRSS_after;
+ unsigned long VmLck_before;
+ unsigned long VmLck_after;
+ unsigned long VmRSS;
+ unsigned long VmLck;
+ char *buf;
+
+ buf = SAFE_MMAP(NULL, MMAPLEN, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ SAFE_FILE_LINES_SCANF("/proc/self/status", "VmRSS: %lu", &VmRSS_before);
+ SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %lu", &VmLck_before);
+
+ SAFE_MLOCK(buf, MMAPLEN);
+
+ SAFE_FILE_LINES_SCANF("/proc/self/status", "VmRSS: %lu", &VmRSS_after);
+ SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %lu", &VmLck_after);
+
+ VmRSS = VmRSS_after - VmRSS_before;
+ VmLck = VmLck_after - VmLck_before;
+
+ // Convertion from KiB to B
+ VmRSS *= 1024;
+ VmLck *= 1024;
+
+ if (VmRSS >= MMAPLEN) {
+ tst_res(TPASS, "Pre-allocation functionality of mlock() successful");
+ } else {
+ tst_brk(TBROK, "Expected pre-allocation of %lu bytes, "
+ "get %lu pre-allocated", MMAPLEN, VmRSS);
+ }
+
+ if (VmLck == MMAPLEN) {
+ tst_res(TPASS, "Locking functionality of mlock() successful");
+ } else {
+ tst_brk(TBROK, "Expected locking of %lu bytes, "
+ "get %lu locked", MMAPLEN, VmLck);
+ }
+
+ SAFE_MUNLOCK(buf, MMAPLEN);
+ SAFE_MUNMAP(buf, MMAPLEN);
+}
+
+static struct tst_test test = {
+ .test_all = verify_mlock,
+};
--
2.44.0
--
Mailing list info: https://lists.linux.it/listinfo/ltp
next reply other threads:[~2024-04-29 9:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 13:48 Filippo Storniolo [this message]
2024-04-29 10:00 ` [LTP] [PATCH] syscalls/mlock05: add mlock test for locking and pre-faulting of memory Cyril Hrubis
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