It is necessary to set fd to -1 when inotify_add_watch() fails in
cg_prepare_for_wait. Otherwise the fd which has been closed in
cg_prepare_for_wait may be misused in other functions such as
cg_enter_and_wait_for_frozen and cg_freeze_wait.
Fixes: 5313bfe425 ("selftests: cgroup: add freezer controller self-tests")
Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Simplify task migration by being oblivious about its PID during
migration. This allows to easily migrate individual threads as well.
This change brings no functional change and prepares grounds for thread
granularity migrating tests.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add a new cgroup freezer selftest, which checks that if a cgroup is
frozen, their new child cgroups will properly inherit the frozen
state.
It creates a parent cgroup, freezes it, creates a child cgroup
and populates it with a dummy process. Then it checks that both
parent and child cgroup are frozen.
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This patch implements 9 tests for the freezer controller for
cgroup v2:
1) a simple test, which aims to freeze and unfreeze a cgroup with 100
processes
2) a more complicated tree test, which creates a hierarchy of cgroups,
puts some processes in some cgroups, and tries to freeze and unfreeze
different parts of the subtree
3) a forkbomb test: the test aims to freeze a forkbomb running in a
cgroup, kill all tasks in the cgroup and remove the cgroup without
the unfreezing.
4) rmdir test: the test creates two nested cgroups, freezes the parent
one, checks that the child can be successfully removed, and a new
child can be created
5) migration tests: the test checks migration of a task between
frozen cgroups: from a frozen to a running, from a running to a
frozen, and from a frozen to a frozen.
6) ptrace test: the test checks that it's possible to attach to
a process in a frozen cgroup, get some information and detach, and
the cgroup will remain frozen.
7) stopped test: the test checks that it's possible to freeze a cgroup
with a stopped task
8) ptraced test: the test checks that it's possible to freeze a cgroup
with a ptraced task
9) vfork test: the test checks that it's possible to freeze a cgroup
with a parent process waiting for the child process in vfork()
Expected output:
$ ./test_freezer
ok 1 test_cgfreezer_simple
ok 2 test_cgfreezer_tree
ok 3 test_cgfreezer_forkbomb
ok 4 test_cgrreezer_rmdir
ok 5 test_cgfreezer_migrate
ok 6 test_cgfreezer_ptrace
ok 7 test_cgfreezer_stopped
ok 8 test_cgfreezer_ptraced
ok 9 test_cgfreezer_vfork
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: kernel-team@fb.com
Cc: linux-kselftest@vger.kernel.org
Hewenliang