- Test mounting and remounting with memcg= succeeds. - Test that simple writes in this file system are charged to the correct memecg. - Test that on non-pagefault paths the calling process gets an ENOSPC. - Test that in pagefault paths the calling process gets a SIGBUS.
Signed-off-by: Mina Almasry almasrymina@google.com
---
Changes in v4:
- Convert tests to expect ENOSPC/SIGBUS rather than ENOMEM oom behavior. - Added remount test.
--- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/mmap_write.c | 103 +++++++++++++++++++ tools/testing/selftests/vm/tmpfs-memcg.sh | 116 ++++++++++++++++++++++ 3 files changed, 220 insertions(+) create mode 100644 tools/testing/selftests/vm/mmap_write.c create mode 100755 tools/testing/selftests/vm/tmpfs-memcg.sh
diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 2e7e86e852828..cb229974c5f15 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -19,6 +19,7 @@ madv_populate userfaultfd mlock-intersect-test mlock-random-test +mmap_write virtual_address_range gup_test va_128TBswitch diff --git a/tools/testing/selftests/vm/mmap_write.c b/tools/testing/selftests/vm/mmap_write.c new file mode 100644 index 0000000000000..88a8468f2128c --- /dev/null +++ b/tools/testing/selftests/vm/mmap_write.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This program faults memory in tmpfs + */ + +#include <err.h> +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/types.h> +#include <sys/shm.h> +#include <sys/stat.h> +#include <sys/mman.h> + +/* Global definitions. */ + +/* Global variables. */ +static const char *self; +static char *shmaddr; +static int shmid; + +/* + * Show usage and exit. + */ +static void exit_usage(void) +{ + printf("Usage: %s -p <path to tmpfs file> -s <size to map>\n", self); + exit(EXIT_FAILURE); +} + +int main(int argc, char **argv) +{ + int fd = 0; + int key = 0; + int *ptr = NULL; + int c = 0; + int size = 0; + char path[256] = ""; + int want_sleep = 0, private = 0; + int populate = 0; + int write = 0; + int reserve = 1; + + /* Parse command-line arguments. */ + setvbuf(stdout, NULL, _IONBF, 0); + self = argv[0]; + + while ((c = getopt(argc, argv, ":s:p:")) != -1) { + switch (c) { + case 's': + size = atoi(optarg); + break; + case 'p': + strncpy(path, optarg, sizeof(path)); + break; + default: + errno = EINVAL; + perror("Invalid arg"); + exit_usage(); + } + } + + printf("%s\n", path); + if (strncmp(path, "", sizeof(path)) != 0) { + printf("Writing to this path: %s\n", path); + } else { + errno = EINVAL; + perror("path not found"); + exit_usage(); + } + + if (size != 0) { + printf("Writing this size: %d\n", size); + } else { + errno = EINVAL; + perror("size not found"); + exit_usage(); + } + + fd = open(path, O_CREAT | O_RDWR, 0777); + if (fd == -1) + err(1, "Failed to open file."); + + if (ftruncate(fd, size)) + err(1, "failed to ftruncate %s", path); + + ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (ptr == MAP_FAILED) { + close(fd); + err(1, "Error mapping the file"); + } + + printf("Writing to memory.\n"); + memset(ptr, 1, size); + printf("Done writing to memory.\n"); + close(fd); + + return 0; +} diff --git a/tools/testing/selftests/vm/tmpfs-memcg.sh b/tools/testing/selftests/vm/tmpfs-memcg.sh new file mode 100755 index 0000000000000..50876992107fd --- /dev/null +++ b/tools/testing/selftests/vm/tmpfs-memcg.sh @@ -0,0 +1,116 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +CGROUP_PATH=/dev/cgroup/memory/tmpfs-memcg-test +REMOUNT_CGROUP_PATH=/dev/cgroup/memory/remount-memcg-test + +function cleanup() { + rm -rf /mnt/tmpfs/* + umount /mnt/tmpfs + rm -rf /mnt/tmpfs + + rmdir $CGROUP_PATH + rmdir $REMOUNT_CGROUP_PATH + + echo CLEANUP DONE +} + +function setup() { + mkdir -p $CGROUP_PATH + mkdir -p $REMOUNT_CGROUP_PATH + echo $((10 * 1024 * 1024)) > $CGROUP_PATH/memory.limit_in_bytes + echo 0 > $CGROUP_PATH/cpuset.cpus + echo 0 > $CGROUP_PATH/cpuset.mems + + mkdir -p /mnt/tmpfs + + echo SETUP DONE +} + +function expect_equal() { + local expected="$1" + local actual="$2" + local error="$3" + + if [[ "$actual" != "$expected" ]]; then + echo "expected ($expected) != actual ($actual): $3" >&2 + cleanup + exit 1 + fi +} + +function expect_ge() { + local expected="$1" + local actual="$2" + local error="$3" + + if [[ "$actual" -lt "$expected" ]]; then + echo "expected ($expected) < actual ($actual): $3" >&2 + cleanup + exit 1 + fi +} + +cleanup +setup + +mount -t tmpfs -o memcg=$REMOUNT_CGROUP_PATH tmpfs /mnt/tmpfs +check=$(cat /proc/mounts | grep -i remount-memcg-test) +if [ -z "$check" ]; then + echo "tmpfs memcg= was not mounted correctly:" + echo $check + echo "FAILED" + cleanup + exit 1 +fi + +mount -t tmpfs -o remount,memcg=$CGROUP_PATH tmpfs /mnt/tmpfs +check=$(cat /proc/mounts | grep -i tmpfs-memcg-test) +if [ -z "$check" ]; then + echo "tmpfs memcg= was not remounted correctly:" + echo $check + echo "FAILED" + cleanup + exit 1 +fi + +TARGET_MEMCG_USAGE=$(cat $CGROUP_PATH/memory.usage_in_bytes) +expect_equal 0 "$TARGET_MEMCG_USAGE" "Before echo, memcg usage should be 0" + +# Echo to allocate a page in the tmpfs +echo +echo +echo hello > /mnt/tmpfs/test +TARGET_MEMCG_USAGE=$(cat $CGROUP_PATH/memory.usage_in_bytes) +expect_ge 4096 "$TARGET_MEMCG_USAGE" "After echo, memcg usage should be greater than 4096" +echo "Echo test succeeded" + +echo +echo +tools/testing/selftests/vm/mmap_write -p /mnt/tmpfs/test -s $((1 * 1024 * 1024)) +TARGET_MEMCG_USAGE=$(cat $CGROUP_PATH/memory.usage_in_bytes) +expect_ge $((1 * 1024 * 1024)) "$TARGET_MEMCG_USAGE" "After mmap_write, memcg usage should greater than 1MB" +echo "WRITE TEST SUCCEEDED" + +# SIGBUS the remote container on pagefault. +echo +echo +echo "SIGBUS the process doing the remote charge on hitting the limit of the remote cgroup." +echo "This will take a long time because the kernel goes through reclaim retries," +echo "but should eventually the write process should receive a SIGBUS" +set +e +tools/testing/selftests/vm/mmap_write -p /mnt/tmpfs/test -s $((11 * 1024 * 1024)) & +wait $! +expect_equal "$?" "135" "mmap_write should have exited with SIGBUS" +set -e + +# ENOSPC the remote container on non pagefault. +echo +echo +echo "OOMing the remote container using cat (non-pagefault)" +echo "This will take a long time because the kernel goes through reclaim retries," +echo "but should eventually the cat command should receive an ENOSPC" +cat /dev/random > /mnt/tmpfs/random || true + +cleanup +echo TEST PASSED -- 2.34.0.rc2.393.gf8c9666880-goog