From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: Re: [PATCH 5/5] tests/cgroup: test cgroup.kill Date: Thu, 29 Apr 2021 21:05:35 -0700 Message-ID: References: <20210429120113.2238065-1-brauner@kernel.org> <20210429120113.2238065-5-brauner@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=X663s2OtcAp3Dk2qRZN17wfTZSt1hP0N7LpNVQVZmkc=; b=RFKMan1IV+ImrfIUEZc65UmXFrJ1hS5mjDUNdkUyEqU3DIh2RuLoO+ItmrWNVdFqMuG4 5sZV7EplB25HDOUsr3riCLgiiQ9/vXtW9YiJOfiwU9qA2qa1p7QXOfO68F5tTHWBLiiN ppDUkAl7lGhOpER8t/zcKBbSBU1mzh/y67Q= Content-Disposition: inline In-Reply-To: <20210429120113.2238065-5-brauner-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-ID: Content-Transfer-Encoding: 7bit To: Christian Brauner Cc: Tejun Heo , Shakeel Butt , Zefan Li , Johannes Weiner , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christian Brauner On Thu, Apr 29, 2021 at 02:01:13PM +0200, Christian Brauner wrote: > From: Christian Brauner > > Test that the new cgroup.kill feature works as intended. > > Cc: Roman Gushchin > Cc: Tejun Heo > Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > Signed-off-by: Christian Brauner > --- > tools/testing/selftests/cgroup/.gitignore | 3 +- > tools/testing/selftests/cgroup/Makefile | 2 + > tools/testing/selftests/cgroup/test_kill.c | 293 +++++++++++++++++++++ > 3 files changed, 297 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/cgroup/test_kill.c > > diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore > index 84cfcabea838..be9643ef6285 100644 > --- a/tools/testing/selftests/cgroup/.gitignore > +++ b/tools/testing/selftests/cgroup/.gitignore > @@ -2,4 +2,5 @@ > test_memcontrol > test_core > test_freezer > -test_kmem > \ No newline at end of file > +test_kmem > +test_kill > diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile > index f027d933595b..87b7b0d90773 100644 > --- a/tools/testing/selftests/cgroup/Makefile > +++ b/tools/testing/selftests/cgroup/Makefile > @@ -9,6 +9,7 @@ TEST_GEN_PROGS = test_memcontrol > TEST_GEN_PROGS += test_kmem > TEST_GEN_PROGS += test_core > TEST_GEN_PROGS += test_freezer > +TEST_GEN_PROGS += test_kill > > include ../lib.mk > > @@ -16,3 +17,4 @@ $(OUTPUT)/test_memcontrol: cgroup_util.c ../clone3/clone3_selftests.h > $(OUTPUT)/test_kmem: cgroup_util.c ../clone3/clone3_selftests.h > $(OUTPUT)/test_core: cgroup_util.c ../clone3/clone3_selftests.h > $(OUTPUT)/test_freezer: cgroup_util.c ../clone3/clone3_selftests.h > +$(OUTPUT)/test_kill: cgroup_util.c ../clone3/clone3_selftests.h > diff --git a/tools/testing/selftests/cgroup/test_kill.c b/tools/testing/selftests/cgroup/test_kill.c > new file mode 100644 > index 000000000000..c4e7b2e87395 > --- /dev/null > +++ b/tools/testing/selftests/cgroup/test_kill.c > @@ -0,0 +1,293 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "../kselftest.h" > +#include "cgroup_util.h" > + > +#define DEBUG > +#ifdef DEBUG > +#define debug(args...) fprintf(stderr, args) > +#else > +#define debug(args...) > +#endif > + > +/* > + * Kill the given cgroup and wait for the inotify signal. > + * If there are no events in 10 seconds, treat this as an error. > + * Then check that the cgroup is in the desired state. > + */ > +static int cg_kill_wait(const char *cgroup) > +{ > + int fd, ret = -1; > + > + fd = cg_prepare_for_wait(cgroup); > + if (fd < 0) > + return fd; > + > + ret = cg_write(cgroup, "cgroup.kill", "1"); > + if (ret) { > + debug("Error: cg_write() failed\n"); > + goto out; > + } > + > + ret = cg_wait_for(fd); > + if (ret) > + goto out; > + > + ret = cg_read_strcmp(cgroup, "cgroup.events", "populated 0\n"); > +out: > + close(fd); > + return ret; > +} > + > +/* > + * A simple process running in a sleep loop until being > + * re-parented. > + */ > +static int child_fn(const char *cgroup, void *arg) > +{ > + int ppid = getppid(); > + > + while (getppid() == ppid) > + usleep(1000); > + > + return getppid() == ppid; > +} > + > +static int test_cgkill_simple(const char *root) > +{ > + int ret = KSFT_FAIL; > + char *cgroup = NULL; > + int i; > + > + cgroup = cg_name(root, "cg_test_simple"); > + if (!cgroup) > + goto cleanup; > + > + if (cg_create(cgroup)) > + goto cleanup; > + > + for (i = 0; i < 100; i++) > + cg_run_nowait(cgroup, child_fn, NULL); > + > + if (cg_wait_for_proc_count(cgroup, 100)) > + goto cleanup; > + > + if (cg_write(cgroup, "cgroup.kill", "1")) > + goto cleanup; > + > + if (cg_read_strcmp(cgroup, "cgroup.events", "populated 1\n")) > + goto cleanup; > + > + if (cg_kill_wait(cgroup)) > + goto cleanup; > + > + if (cg_read_strcmp(cgroup, "cgroup.events", "populated 0\n")) > + goto cleanup; > + > + ret = KSFT_PASS; > + > +cleanup: > + if (cgroup) > + cg_destroy(cgroup); > + free(cgroup); > + return ret; > +} > + > +/* > + * The test creates the following hierarchy: > + * A > + * / / \ \ > + * B E I K > + * /\ | > + * C D F > + * | > + * G > + * | > + * H > + * > + * with a process in C, H and 3 processes in K. > + * Then it tries to kill the whole tree. > + */ > +static int test_cgkill_tree(const char *root) > +{ > + char *cgroup[10] = {0}; > + int ret = KSFT_FAIL; > + int i; > + > + cgroup[0] = cg_name(root, "cg_test_tree_A"); > + if (!cgroup[0]) > + goto cleanup; > + > + cgroup[1] = cg_name(cgroup[0], "B"); > + if (!cgroup[1]) > + goto cleanup; > + > + cgroup[2] = cg_name(cgroup[1], "C"); > + if (!cgroup[2]) > + goto cleanup; > + > + cgroup[3] = cg_name(cgroup[1], "D"); > + if (!cgroup[3]) > + goto cleanup; > + > + cgroup[4] = cg_name(cgroup[0], "E"); > + if (!cgroup[4]) > + goto cleanup; > + > + cgroup[5] = cg_name(cgroup[4], "F"); > + if (!cgroup[5]) > + goto cleanup; > + > + cgroup[6] = cg_name(cgroup[5], "G"); > + if (!cgroup[6]) > + goto cleanup; > + > + cgroup[7] = cg_name(cgroup[6], "H"); > + if (!cgroup[7]) > + goto cleanup; > + > + cgroup[8] = cg_name(cgroup[0], "I"); > + if (!cgroup[8]) > + goto cleanup; > + > + cgroup[9] = cg_name(cgroup[0], "K"); > + if (!cgroup[9]) > + goto cleanup; > + > + for (i = 0; i < 10; i++) > + if (cg_create(cgroup[i])) > + goto cleanup; > + > + cg_run_nowait(cgroup[2], child_fn, NULL); > + cg_run_nowait(cgroup[7], child_fn, NULL); > + cg_run_nowait(cgroup[9], child_fn, NULL); > + cg_run_nowait(cgroup[9], child_fn, NULL); > + cg_run_nowait(cgroup[9], child_fn, NULL); > + > + /* > + * Wait until all child processes will enter > + * corresponding cgroups. > + */ > + > + if (cg_wait_for_proc_count(cgroup[2], 1) || > + cg_wait_for_proc_count(cgroup[7], 1) || > + cg_wait_for_proc_count(cgroup[9], 3)) > + goto cleanup; > + > + /* > + * Kill A and check that we get an empty notification. > + */ > + if (cg_kill_wait(cgroup[0])) > + goto cleanup; > + > + if (cg_read_strcmp(cgroup[0], "cgroup.events", "populated 0\n")) > + goto cleanup; > + > + ret = KSFT_PASS; > + > +cleanup: > + for (i = 9; i >= 0 && cgroup[i]; i--) { > + cg_destroy(cgroup[i]); > + free(cgroup[i]); > + } > + > + return ret; > +} > + > +static int forkbomb_fn(const char *cgroup, void *arg) > +{ > + int ppid; > + > + fork(); > + fork(); > + > + ppid = getppid(); > + > + while (getppid() == ppid) > + usleep(1000); > + > + return getppid() == ppid; > +} > + > +/* > + * The test runs a fork bomb in a cgroup and tries to kill it. > + */ > +static int test_cgkill_forkbomb(const char *root) > +{ > + int ret = KSFT_FAIL; > + char *cgroup = NULL; > + > + cgroup = cg_name(root, "cg_forkbomb_test"); > + if (!cgroup) > + goto cleanup; > + > + if (cg_create(cgroup)) > + goto cleanup; > + > + cg_run_nowait(cgroup, forkbomb_fn, NULL); > + > + usleep(100000); > + > + if (cg_kill_wait(cgroup)) > + goto cleanup; > + > + if (cg_wait_for_proc_count(cgroup, 0)) > + goto cleanup; > + > + ret = KSFT_PASS; > + > +cleanup: > + if (cgroup) > + cg_destroy(cgroup); > + free(cgroup); > + return ret; > +} > + > +#define T(x) { x, #x } > +struct cgkill_test { > + int (*fn)(const char *root); > + const char *name; > +} tests[] = { > + T(test_cgkill_simple), > + T(test_cgkill_tree), > + T(test_cgkill_forkbomb), I'm a little bit worried about the forkbomb test: how reliable it is and won't it kill the system, but Idk how make it better. Maybe instead of a true fork bomb we need to spawn children by a single process? I'm not exactly sure. Other than that the patch looks good to me. And thank you for writing tests! Roman