[LTP] [PATCH v1] Add process_madvise01 test

Andrea Cervesato andrea.cervesato@suse.de
Tue Aug 22 15:46:04 CEST 2023


From: Andrea Cervesato <andrea.cervesato@suse.com>

This test checks process_madvise support for MADV_PAGEOUT. It tests
if memory pages have been swapped out by looking at smaps information
after reclaiming memory using MADV_PAGEOUT.
This test supports kernel 5.10 or later.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 testcases/kernel/syscalls/cma/cma.h           | 101 ++++++++++++++
 .../kernel/syscalls/cma/process_madvise01.c   | 124 ++++++++++++++++++
 2 files changed, 225 insertions(+)
 create mode 100644 testcases/kernel/syscalls/cma/cma.h
 create mode 100644 testcases/kernel/syscalls/cma/process_madvise01.c

diff --git a/testcases/kernel/syscalls/cma/cma.h b/testcases/kernel/syscalls/cma/cma.h
new file mode 100644
index 000000000..08a0d9319
--- /dev/null
+++ b/testcases/kernel/syscalls/cma/cma.h
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+#ifndef CMA_H__
+#define CMA_H__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "tst_safe_stdio.h"
+
+struct addr_mapping {
+	int size;
+	int rss;
+	int pss;
+	int shared_clean;
+	int shared_dirty;
+	int private_clean;
+	int private_dirty;
+	int referenced;
+	int anonymous;
+	int anon_huge_pages;
+	int shmem_huge_pages;
+	int shmem_pmd_mapped;
+	int swap;
+	int kernel_page_size;
+	int mmu_page_size;
+	int locked;
+	int protection_key;
+};
+
+static inline void read_address_mapping(unsigned long address, struct addr_mapping *mapping)
+{
+	FILE *f;
+	int found = 0;
+	char label[BUFSIZ];
+	char line[BUFSIZ];
+	char smaps[BUFSIZ];
+	char ptr_str[BUFSIZ];
+	int value;
+
+	snprintf(smaps, BUFSIZ, "/proc/%i/smaps", getpid());
+	snprintf(ptr_str, BUFSIZ, "%lx", address);
+
+	f = SAFE_FOPEN(smaps, "r");
+
+	while (fgets(line, BUFSIZ, f) != NULL) {
+		if (strncmp(ptr_str, line, strlen(ptr_str)) == 0)
+			found = 1;
+
+		if (!found)
+			continue;
+
+		if (found && strcmp(line, "VmFlags") >= 0)
+			break;
+
+		if (sscanf(line, "%31[^:]: %d", label, &value) > 0) {
+			if (strcmp(label, "Size") == 0)
+				mapping->size = value;
+			else if (strcmp(label, "Rss") == 0)
+				mapping->rss = value;
+			else if (strcmp(label, "Pss") == 0)
+				mapping->pss = value;
+			else if (strcmp(label, "Shared_Clean") == 0)
+				mapping->shared_clean = value;
+			else if (strcmp(label, "Shared_Dirty") == 0)
+				mapping->shared_dirty = value;
+			else if (strcmp(label, "Private_Clean") == 0)
+				mapping->private_clean = value;
+			else if (strcmp(label, "Private_Dirty") == 0)
+				mapping->private_dirty = value;
+			else if (strcmp(label, "Referenced") == 0)
+				mapping->referenced = value;
+			else if (strcmp(label, "Anonymous") == 0)
+				mapping->anonymous = value;
+			else if (strcmp(label, "AnonHugePages") == 0)
+				mapping->anon_huge_pages = value;
+			else if (strcmp(label, "ShmemHugePages") == 0)
+				mapping->shmem_huge_pages = value;
+			else if (strcmp(label, "ShmemPmdMapped") == 0)
+				mapping->shmem_pmd_mapped = value;
+			else if (strcmp(label, "Swap") == 0)
+				mapping->swap = value;
+			else if (strcmp(label, "KernelPageSize") == 0)
+				mapping->kernel_page_size = value;
+			else if (strcmp(label, "MMUPageSize") == 0)
+				mapping->mmu_page_size = value;
+			else if (strcmp(label, "Locked") == 0)
+				mapping->locked = value;
+			else if (strcmp(label, "ProtectionKey") == 0)
+				mapping->protection_key = value;
+		}
+	}
+
+	SAFE_FCLOSE(f);
+}
+
+#endif
diff --git a/testcases/kernel/syscalls/cma/process_madvise01.c b/testcases/kernel/syscalls/cma/process_madvise01.c
new file mode 100644
index 000000000..ea3e0270d
--- /dev/null
+++ b/testcases/kernel/syscalls/cma/process_madvise01.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Allocate anonymous memory pages inside child and reclaim it with
+ * MADV_PAGEOUT. Then check if memory pages have been swapped out by looking
+ * at smaps information.
+ *
+ * The advice might be ignored for some pages in the range when it is
+ * not applicable, so test passes if swap memory increases after
+ * reclaiming memory with MADV_PAGEOUT.
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/mman.h>
+#include "tst_test.h"
+#include "lapi/mmap.h"
+#include "lapi/syscalls.h"
+#include "cma.h"
+
+#define MEM_CHILD	(1 * TST_MB)
+
+static void **data_ptr;
+
+static void child_alloc(void)
+{
+	char data[MEM_CHILD];
+	struct addr_mapping map_before;
+	struct addr_mapping map_after;
+
+	memset(data, 'a', MEM_CHILD);
+
+	tst_res(TINFO, "Allocate memory: %d bytes", MEM_CHILD);
+
+	*data_ptr = SAFE_MMAP(NULL, MEM_CHILD,
+			PROT_READ | PROT_WRITE,
+			MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+
+	memset(*data_ptr, 'a', MEM_CHILD);
+
+	memset(&map_before, 0, sizeof(struct addr_mapping));
+	read_address_mapping((unsigned long)*data_ptr, &map_before);
+
+	TST_CHECKPOINT_WAKE_AND_WAIT(0);
+
+	memset(&map_after, 0, sizeof(struct addr_mapping));
+	read_address_mapping((unsigned long)*data_ptr, &map_after);
+
+	if (memcmp(*data_ptr, data, MEM_CHILD) != 0) {
+		tst_res(TFAIL, "Dirty memory after reclaiming it");
+		return;
+	}
+
+	SAFE_MUNMAP(*data_ptr, MEM_CHILD);
+	*data_ptr = NULL;
+
+    TST_EXP_EXPR(map_before.swap < map_after.swap,
+        "Most of the memory has been swapped out: %dkB",
+        map_after.swap);
+}
+
+static void setup(void)
+{
+	data_ptr = SAFE_MMAP(NULL, sizeof(void *),
+			PROT_READ | PROT_WRITE,
+			MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+}
+
+static void cleanup(void)
+{
+	if (*data_ptr)
+		SAFE_MUNMAP(*data_ptr, MEM_CHILD);
+
+	if (data_ptr)
+		SAFE_MUNMAP(data_ptr, sizeof(void *));
+}
+
+static void run(void)
+{
+	int ret;
+	int pidfd;
+	pid_t pid_alloc;
+	struct iovec vec;
+
+	pid_alloc = SAFE_FORK();
+	if (!pid_alloc) {
+		child_alloc();
+		return;
+	}
+
+	TST_CHECKPOINT_WAIT(0);
+
+	tst_res(TINFO, "Reclaim memory using MADV_PAGEOUT");
+
+	pidfd = SAFE_PIDFD_OPEN(pid_alloc, 0);
+
+	vec.iov_base = *data_ptr;
+	vec.iov_len = MEM_CHILD;
+
+	ret = tst_syscall(__NR_process_madvise, pidfd, &vec, 1UL,
+			MADV_PAGEOUT, 0UL);
+
+	if (ret == -1)
+		tst_brk(TBROK | TERRNO, "process_madvise failed");
+
+	if (ret != MEM_CHILD)
+		tst_brk(TBROK, "process_madvise reclaimed only %d bytes", ret);
+
+	TST_CHECKPOINT_WAKE(0);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run,
+	.forks_child = 1,
+	.min_kver = "5.10",
+	.needs_checkpoints = 1,
+};
-- 
2.35.3



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