From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roman Gushchin <guro@fb.com>
Subject: Re: [PATCH v10 6/9] kselftests: cgroup: add freezer controller
 self-tests
Date: Wed, 17 Jul 2019 00:49:09 +0000
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To: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Roman Gushchin <guroan@gmail.com>, Tejun Heo <tj@kernel.org>, Oleg Nesterov <oleg@redhat.com>, Kernel Team <Kernel-team@fb.com>, "cgroups@vger.kernel.org" <cgroups@vger.kernel.org>, open list <linux-kernel@vger.kernel.org>, Shuah Khan <shuah@kernel.org>, "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org>, "lkft-triage@lists.linaro.org" <lkft-triage@lists.linaro.org>

On Tue, Jul 16, 2019 at 08:18:39PM +0530, Naresh Kamboju wrote:
> Hi Roman,
>=20
> Just want to share information here on what we notice on running this tes=
t case,

Hi Naresh!

Thank you for the report!

The interaction between ptrace and freezer is complicated
(as ptrace in general),so there are known cases when spurious
cgroup transitions (frozen <-> non frozen <-> frozen ) can happen.

Does it create any difficulties? If so, I'll send a diff to ignore
the result of this test for now.

Thank you!

>=20
> On Fri, 5 Apr 2019 at 23:17, Roman Gushchin <guroan@gmail.com> wrote:
> >
> > This patch implements 9 tests for the freezer controller for
> > cgroup v2:
> ...
> > 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.
>=20
> selftests cgroup test_freezer failed because of the sys entry path not fo=
und.

Can you, please, elaborate on this?

>  Cgroup /sys/fs/cgroup/unified/cg_test_ptrace isn't frozen
> /sys/fs/cgroup/unified/cg_test_ptrace: isn't_frozen #
> # not ok 6 test_cgfreezer_ptrace
>=20
> This test case fails intermittently.

Thank you!