Nicholas Piggin <npig...@gmail.com> writes:
> There is no need to use /dev/shm for file-backed memory devices, and
> it is too small to be usable in gitlab CI. Switch to using a regular
> file in /tmp/ which will usually have more space available.
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
> Am I missing something? AFAIKS there is not even any point using
> /dev/shm aka tmpfs anyway, there is not much special about it as a
> filesystem. This applies on top of the series just sent, and passes
> gitlab CI qtests including aarch64.
/dev/shm however will be mounted on tmpfs while /tmp may not. I don't
know if this has any implication to this test. Probably not.
>
> Thanks,
> Nick
>
> tests/qtest/migration-test.c | 41 ++++++++++++------------------------
> 1 file changed, 13 insertions(+), 28 deletions(-)
>
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 45830eb213..86eace354e 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -552,7 +552,7 @@ typedef struct {
> * unconditionally, because it means the user would like to be verbose.
> */
> bool hide_stderr;
> - bool use_shmem;
> + bool use_memfile;
> /* only launch the target process */
> bool only_target;
> /* Use dirty ring if true; dirty logging otherwise */
> @@ -672,29 +672,14 @@ static int test_migrate_start(QTestState **from,
> QTestState **to,
> g_autofree gchar *cmd_source = NULL;
> g_autofree gchar *cmd_target = NULL;
> const gchar *ignore_stderr;
> - g_autofree char *shmem_opts = NULL;
> - g_autofree char *shmem_path = NULL;
> + g_autofree char *memfile_opts = NULL;
> + g_autofree char *memfile_path = NULL;
> const char *kvm_opts = NULL;
> const char *arch = qtest_get_arch();
> const char *memory_size;
> const char *machine_alias, *machine_opts = "";
> g_autofree char *machine = NULL;
>
> - if (args->use_shmem) {
> - if (!g_file_test("/dev/shm", G_FILE_TEST_IS_DIR)) {
> - g_test_skip("/dev/shm is not supported");
> - return -1;
> - }
> - if (getenv("GITLAB_CI")) {
> - /*
> - * Gitlab runners are limited to 64MB shm size. See:
> - * https://lore.kernel.org/all/87ttq5fvh7....@suse.de/
> - */
> - g_test_skip("/dev/shm is not supported in Gitlab CI
> environment");
> - return -1;
> - }
> - }
> -
> dst_state = (QTestMigrationState) { };
> src_state = (QTestMigrationState) { };
> bootfile_create(tmpfs, args->suspend_me);
> @@ -754,12 +739,12 @@ static int test_migrate_start(QTestState **from,
> QTestState **to,
> ignore_stderr = "";
> }
>
> - if (args->use_shmem) {
> - shmem_path = g_strdup_printf("/dev/shm/qemu-%d", getpid());
> - shmem_opts = g_strdup_printf(
> + if (args->use_memfile) {
> + memfile_path = g_strdup_printf("/%s/qemu-%d", tmpfs, getpid());
The variable tmpfs already contains the leading slash. Strictly speaking
we don't need the pid because 'tmpfs' is unique for each migration-test
run. If you use a fixed string such as qemu-mem, you can then clean it
up at test_migrate_end() along with the others.
> + memfile_opts = g_strdup_printf(
> "-object memory-backend-file,id=mem0,size=%s"
> ",mem-path=%s,share=on -numa node,memdev=mem0",
> - memory_size, shmem_path);
> + memory_size, memfile_path);
> }
>
> if (args->use_dirty_ring) {
> @@ -788,7 +773,7 @@ static int test_migrate_start(QTestState **from,
> QTestState **to,
> memory_size, tmpfs,
> arch_opts ? arch_opts : "",
> arch_source ? arch_source : "",
> - shmem_opts ? shmem_opts : "",
> + memfile_opts ? memfile_opts : "",
> args->opts_source ? args->opts_source : "",
> ignore_stderr);
> if (!args->only_target) {
> @@ -810,7 +795,7 @@ static int test_migrate_start(QTestState **from,
> QTestState **to,
> memory_size, tmpfs, uri,
> arch_opts ? arch_opts : "",
> arch_target ? arch_target : "",
> - shmem_opts ? shmem_opts : "",
> + memfile_opts ? memfile_opts : "",
> args->opts_target ? args->opts_target : "",
> ignore_stderr);
> *to = qtest_init_with_env(QEMU_ENV_DST, cmd_target);
> @@ -822,8 +807,8 @@ static int test_migrate_start(QTestState **from,
> QTestState **to,
> * Remove shmem file immediately to avoid memory leak in test failed
> case.
> * It's valid because QEMU has already opened this file
> */
I'm not sure what memory leak this referred to. When a test fails
anywhere outside test_migrate_end(), the /tmp/migration-test-XXXX
directory will stay behind with all the files used during the test. We
probably don't need the special case for this one file.
$ ls /tmp/migration-test-*/
/tmp/migration-test-GFO6N2/:
tlscredsx5090
/tmp/migration-test-QH2MO2/:
bootsect dest_serial src_serial
> - if (args->use_shmem) {
> - unlink(shmem_path);
> + if (args->use_memfile) {
> + unlink(memfile_path);
> }
>
> return 0;
> @@ -1875,7 +1860,7 @@ static void test_ignore_shared(void)
> g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
> QTestState *from, *to;
> MigrateStart args = {
> - .use_shmem = true,
> + .use_memfile = true,
> };
>
> if (test_migrate_start(&from, &to, uri, &args)) {
> @@ -2033,7 +2018,7 @@ static void test_mode_reboot(void)
> g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
> FILE_TEST_FILENAME);
> MigrateCommon args = {
> - .start.use_shmem = true,
> + .start.use_memfile = true,
> .connect_uri = uri,
> .listen_uri = "defer",
> .start_hook = test_mode_reboot_start
