Re: [LTP] [PATCH v4] kill01: New case cgroup kill

Li Wang
2023-03-07T11:23:54Z

On Tue, Mar 7, 2023 at 4:28 PM Wei Gao <wegao@suse.com> wrote:

> On Tue, Mar 07, 2023 at 03:13:56PM +0800, Li Wang wrote:
> > Hi Wei,
> >
> > The new test generally looks good to me.
> >
> > I'm thinking maybe we make use of guarded buffers which could
> > remove the setup/cleanup function then. And doing memset(buf,...)
> > before reading into buf[] is quite necessary, to avoid someone
> > running this test with parameter '-i N' that the buf[] is polluted
> > by the first time.
> >
> >
> https://github.com/linux-test-project/ltp/blob/master/doc/c-test-api.txt#L1799
> >
> > <
> https://github.com/linux-test-project/ltp/blob/master/doc/c-test-api.txt#L1799
> >
> > e.g.
>
> I have tried use guarded buffers but compile can not pass.
> Following error will trigger since buf_len is caculate instead of FIX
> constant. So
> I suppose we can not use guarded buffers?
>

Sure, it doesn't matter.
You used an uncertain variable in .size of tst_buffer, that's why it throws
out the compiling error.

>
> kill01.c:131:34: error: initializer element is not constant
> .bufs = (struct tst_buffers []) {
>
> For memset before reading buf issue, i will update in next patch.
>
> >
> > --- a/testcases/kernel/controllers/kill/kill01.c
> > +++ b/testcases/kernel/controllers/kill/kill01.c
> > @@ -26,7 +26,7 @@
> >
> > #define MAX_PID_NUM 100
> > #define pid_num MIN(MAX_PID_NUM, (tst_ncpus_available() + 1))
> > -#define buf_len (20 * pid_num)
> > +#define buf_len (10 * MAX_PID_NUM)
> >
> > static char *buf;
> > static struct tst_cg_group *cg_child_test_simple;
> > @@ -60,7 +60,6 @@ static void child_fn(void)
> >
> > while (getppid() == ppid)
> > usleep(1000);
> > -
> > }
> >
> > static int cg_run_nowait(const struct tst_cg_group *const cg,
> > @@ -82,6 +81,8 @@ static int cg_wait_for_proc_count(const struct
> > tst_cg_group *cg, int count)
> > int attempts;
> > char *ptr;
> >
> > + memset(buf, 0, buf_len);
> > +
> > for (attempts = 100; attempts >= 0; attempts--) {
> > int nr = 0;
> >
> > @@ -121,23 +122,14 @@ static void run(void)
> > cg_child_test_simple = tst_cg_group_rm(cg_child_test_simple);
> > }
> >
> > -static void setup(void)
> > -{
> > - buf = SAFE_MALLOC(buf_len);
> > - memset(buf, 0, buf_len);
> > -}
> > -
> > -static void cleanup(void)
> > -{
> > - free(buf);
> > -}
> > -
> > static struct tst_test test = {
> > .test_all = run,
> > - .setup = setup,
> > - .cleanup = cleanup,
> > .forks_child = 1,
> > .max_runtime = 15,
> > .needs_cgroup_ctrls = (const char *const []){ "memory", NULL },
> > .needs_cgroup_ver = TST_CG_V2,
> > + .bufs = (struct tst_buffers []) {
> > + {&buf, .size = buf_len},
> > + {}
> > + }
> > };
> >
> > Anyway this version you could add my reviewed-by:
> >
> > Reviewed-by: Li Wang <liwang@redhat.com>
> >
> >
> > --
> > Regards,
> > Li Wang
>
>

--
Regards,
Li Wang