The quilt patch titled
Subject: selftests: add selftests for cachestat
has been removed from the -mm tree. Its filename was
selftests-add-selftests-for-cachestat.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Nhat Pham <nphamcs@xxxxxxxxx>
Subject: selftests: add selftests for cachestat
Date: Tue, 2 May 2023 18:36:08 -0700
Test cachestat on a newly created file, /dev/ files, /proc/ files and a
directory. Also test on a shmem file (which can also be tested with
huge pages since tmpfs supports huge pages).
[colin.i.king@xxxxxxxxx: fix spelling mistake "trucate" -> "truncate"]
Link: https://lkml.kernel.org/r/20230505110855.2493457-1-colin.i.king@xxxxxxxxx
[mpe@xxxxxxxxxxxxxx: avoid excessive stack allocation]
Link: https://lkml.kernel.org/r/877ctfa6yv.fsf@mail.lhotse
Link: https://lkml.kernel.org/r/20230503013608.2431726-4-nphamcs@xxxxxxxxx
Signed-off-by: Nhat Pham <nphamcs@xxxxxxxxx>
Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Brian Foster <bfoster@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Colin Ian King <colin.i.king@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
MAINTAINERS | 7
tools/testing/selftests/Makefile | 1
tools/testing/selftests/cachestat/.gitignore | 2
tools/testing/selftests/cachestat/Makefile | 8
tools/testing/selftests/cachestat/test_cachestat.c | 269 +++++++++++
5 files changed, 287 insertions(+)
--- a/MAINTAINERS~selftests-add-selftests-for-cachestat
+++ a/MAINTAINERS
@@ -4486,6 +4486,13 @@ S: Supported
F: Documentation/filesystems/caching/cachefiles.rst
F: fs/cachefiles/
+CACHESTAT: PAGE CACHE STATS FOR A FILE
+M: Nhat Pham <nphamcs@xxxxxxxxx>
+M: Johannes Weiner <hannes@xxxxxxxxxxx>
+L: linux-mm@xxxxxxxxx
+S: Maintained
+F: tools/testing/selftests/cachestat/test_cachestat.c
+
CADENCE MIPI-CSI2 BRIDGES
M: Maxime Ripard <mripard@xxxxxxxxxx>
L: linux-media@xxxxxxxxxxxxxxx
--- /dev/null
+++ a/tools/testing/selftests/cachestat/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+test_cachestat
--- /dev/null
+++ a/tools/testing/selftests/cachestat/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+TEST_GEN_PROGS := test_cachestat
+
+CFLAGS += $(KHDR_INCLUDES)
+CFLAGS += -Wall
+CFLAGS += -lrt
+
+include ../lib.mk
--- /dev/null
+++ a/tools/testing/selftests/cachestat/test_cachestat.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <linux/kernel.h>
+#include <linux/mman.h>
+#include <sys/mman.h>
+#include <sys/shm.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "../kselftest.h"
+
+static const char * const dev_files[] = {
+ "/dev/zero", "/dev/null", "/dev/urandom",
+ "/proc/version", "/proc"
+};
+static const int cachestat_nr = 451;
+
+void print_cachestat(struct cachestat *cs)
+{
+ ksft_print_msg(
+ "Using cachestat: Cached: %lu, Dirty: %lu, Writeback: %lu, Evicted: %lu, Recently Evicted: %lu\n",
+ cs->nr_cache, cs->nr_dirty, cs->nr_writeback,
+ cs->nr_evicted, cs->nr_recently_evicted);
+}
+
+bool write_exactly(int fd, size_t filesize)
+{
+ int random_fd = open("/dev/urandom", O_RDONLY);
+ char *cursor, *data;
+ int remained;
+ bool ret;
+
+ if (random_fd < 0) {
+ ksft_print_msg("Unable to access urandom.\n");
+ ret = false;
+ goto out;
+ }
+
+ data = malloc(filesize);
+ if (!data) {
+ ksft_print_msg("Unable to allocate data.\n");
+ ret = false;
+ goto close_random_fd;
+ }
+
+ remained = filesize;
+ cursor = data;
+
+ while (remained) {
+ ssize_t read_len = read(random_fd, cursor, remained);
+
+ if (read_len <= 0) {
+ ksft_print_msg("Unable to read from urandom.\n");
+ ret = false;
+ goto out_free_data;
+ }
+
+ remained -= read_len;
+ cursor += read_len;
+ }
+
+ /* write random data to fd */
+ remained = filesize;
+ cursor = data;
+ while (remained) {
+ ssize_t write_len = write(fd, cursor, remained);
+
+ if (write_len <= 0) {
+ ksft_print_msg("Unable write random data to file.\n");
+ ret = false;
+ goto out_free_data;
+ }
+
+ remained -= write_len;
+ cursor += write_len;
+ }
+
+ ret = true;
+out_free_data:
+ free(data);
+close_random_fd:
+ close(random_fd);
+out:
+ return ret;
+}
+
+/*
+ * Open/create the file at filename, (optionally) write random data to it
+ * (exactly num_pages), then test the cachestat syscall on this file.
+ *
+ * If test_fsync == true, fsync the file, then check the number of dirty
+ * pages.
+ */
+bool test_cachestat(const char *filename, bool write_random, bool create,
+ bool test_fsync, unsigned long num_pages, int open_flags,
+ mode_t open_mode)
+{
+ size_t PS = sysconf(_SC_PAGESIZE);
+ int filesize = num_pages * PS;
+ bool ret = true;
+ long syscall_ret;
+ struct cachestat cs;
+ struct cachestat_range cs_range = { 0, filesize };
+
+ int fd = open(filename, open_flags, open_mode);
+
+ if (fd == -1) {
+ ksft_print_msg("Unable to create/open file.\n");
+ ret = false;
+ goto out;
+ } else {
+ ksft_print_msg("Create/open %s\n", filename);
+ }
+
+ if (write_random) {
+ if (!write_exactly(fd, filesize)) {
+ ksft_print_msg("Unable to access urandom.\n");
+ ret = false;
+ goto out1;
+ }
+ }
+
+ syscall_ret = syscall(cachestat_nr, fd, &cs_range, &cs, 0);
+
+ ksft_print_msg("Cachestat call returned %ld\n", syscall_ret);
+
+ if (syscall_ret) {
+ ksft_print_msg("Cachestat returned non-zero.\n");
+ ret = false;
+ goto out1;
+
+ } else {
+ print_cachestat(&cs);
+
+ if (write_random) {
+ if (cs.nr_cache + cs.nr_evicted != num_pages) {
+ ksft_print_msg(
+ "Total number of cached and evicted pages is off.\n");
+ ret = false;
+ }
+ }
+ }
+
+ if (test_fsync) {
+ if (fsync(fd)) {
+ ksft_print_msg("fsync fails.\n");
+ ret = false;
+ } else {
+ syscall_ret = syscall(cachestat_nr, fd, &cs_range, &cs, 0);
+
+ ksft_print_msg("Cachestat call (after fsync) returned %ld\n",
+ syscall_ret);
+
+ if (!syscall_ret) {
+ print_cachestat(&cs);
+
+ if (cs.nr_dirty) {
+ ret = false;
+ ksft_print_msg(
+ "Number of dirty should be zero after fsync.\n");
+ }
+ } else {
+ ksft_print_msg("Cachestat (after fsync) returned non-zero.\n");
+ ret = false;
+ goto out1;
+ }
+ }
+ }
+
+out1:
+ close(fd);
+
+ if (create)
+ remove(filename);
+out:
+ return ret;
+}
+
+bool test_cachestat_shmem(void)
+{
+ size_t PS = sysconf(_SC_PAGESIZE);
+ size_t filesize = PS * 512 * 2; /* 2 2MB huge pages */
+ int syscall_ret;
+ size_t compute_len = PS * 512;
+ struct cachestat_range cs_range = { PS, compute_len };
+ char *filename = "tmpshmcstat";
+ struct cachestat cs;
+ bool ret = true;
+ unsigned long num_pages = compute_len / PS;
+ int fd = shm_open(filename, O_CREAT | O_RDWR, 0600);
+
+ if (fd < 0) {
+ ksft_print_msg("Unable to create shmem file.\n");
+ ret = false;
+ goto out;
+ }
+
+ if (ftruncate(fd, filesize)) {
+ ksft_print_msg("Unable to truncate shmem file.\n");
+ ret = false;
+ goto close_fd;
+ }
+
+ if (!write_exactly(fd, filesize)) {
+ ksft_print_msg("Unable to write to shmem file.\n");
+ ret = false;
+ goto close_fd;
+ }
+
+ syscall_ret = syscall(cachestat_nr, fd, &cs_range, &cs, 0);
+
+ if (syscall_ret) {
+ ksft_print_msg("Cachestat returned non-zero.\n");
+ ret = false;
+ goto close_fd;
+ } else {
+ print_cachestat(&cs);
+ if (cs.nr_cache + cs.nr_evicted != num_pages) {
+ ksft_print_msg(
+ "Total number of cached and evicted pages is off.\n");
+ ret = false;
+ }
+ }
+
+close_fd:
+ shm_unlink(filename);
+out:
+ return ret;
+}
+
+int main(void)
+{
+ int ret = 0;
+
+ for (int i = 0; i < 5; i++) {
+ const char *dev_filename = dev_files[i];
+
+ if (test_cachestat(dev_filename, false, false, false,
+ 4, O_RDONLY, 0400))
+ ksft_test_result_pass("cachestat works with %s\n", dev_filename);
+ else {
+ ksft_test_result_fail("cachestat fails with %s\n", dev_filename);
+ ret = 1;
+ }
+ }
+
+ if (test_cachestat("tmpfilecachestat", true, true,
+ true, 4, O_CREAT | O_RDWR, 0400 | 0600))
+ ksft_test_result_pass("cachestat works with a normal file\n");
+ else {
+ ksft_test_result_fail("cachestat fails with normal file\n");
+ ret = 1;
+ }
+
+ if (test_cachestat_shmem())
+ ksft_test_result_pass("cachestat works with a shmem file\n");
+ else {
+ ksft_test_result_fail("cachestat fails with a shmem file\n");
+ ret = 1;
+ }
+
+ return ret;
+}
--- a/tools/testing/selftests/Makefile~selftests-add-selftests-for-cachestat
+++ a/tools/testing/selftests/Makefile
@@ -4,6 +4,7 @@ TARGETS += amd-pstate
TARGETS += arm64
TARGETS += bpf
TARGETS += breakpoints
+TARGETS += cachestat
TARGETS += capabilities
TARGETS += cgroup
TARGETS += clone3
_
Patches currently in -mm which might be from nphamcs@xxxxxxxxx are
