Re: [PATCH bpf-next v3 8/8] bpf: add a selftest for cgroup hierarchical stats collection

From: Yonghong Song <yhs@fb.com>
To: Hao Luo <haoluo@google.com>
Cc: "Yosry Ahmed" <yosryahmed@google.com>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Tejun Heo" <tj@kernel.org>,
	"Zefan Li" <lizefan.x@bytedance.com>,
	"Johannes Weiner" <hannes@cmpxchg.org>,
	"Shuah Khan" <shuah@kernel.org>,
	"Michal Hocko" <mhocko@kernel.org>,
	"KP Singh" <kpsingh@kernel.org>,
	"Benjamin Tissoires" <benjamin.tissoires@redhat.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Michal Koutný" <mkoutny@suse.com>,
	"Roman Gushchin" <roman.gushchin@linux.dev>,
	"David Rientjes" <rientjes@google.com>,
	"Stanislav Fomichev" <sdf@google.com>,
	"Greg Thelen" <gthelen@google.com>,
	"Shakeel Butt" <shakeelb@google.com>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [PATCH bpf-next v3 8/8] bpf: add a selftest for cgroup hierarchical stats collection
Date: Sun, 10 Jul 2022 23:19:15 -0700	[thread overview]
Message-ID: <e2f8fcd8-9219-1119-86ca-69714789d494@fb.com> (raw)
In-Reply-To: <CA+khW7gu73pRFi73BR20OCJhzrs8-kHfTYYR38+MJUpt6wqXoA@mail.gmail.com>

On 7/10/22 11:01 PM, Hao Luo wrote:
> On Sun, Jul 10, 2022 at 5:51 PM Yonghong Song <yhs@fb.com> wrote:
>>
>>
>>
>> On 7/10/22 5:26 PM, Yonghong Song wrote:
> [...]
>>
>> BTW, CI also reported the test failure.
>> https://github.com/kernel-patches/bpf/pull/3284
>>
>> For example, with gcc built kernel,
>> https://github.com/kernel-patches/bpf/runs/7272407890?check_suite_focus=true
>>
>> The error:
>>
>>     get_cgroup_vmscan_delay:PASS:cgroup_id 0 nsec
>>     get_cgroup_vmscan_delay:PASS:vmscan_reading 0 nsec
>>     check_vmscan_stats:FAIL:child1_vmscan unexpected child1_vmscan:
>> actual 28390910 != expected 28390909
>>     check_vmscan_stats:FAIL:child2_vmscan unexpected child2_vmscan:
>> actual 0 != expected -2
>>     check_vmscan_stats:PASS:test_vmscan 0 nsec
>>     check_vmscan_stats:PASS:root_vmscan 0 nsec
>>
> 
> Yonghong,
> 
> I noticed that the test only failed on test_progs-no_alu32, not
> test_progs. test_progs passed. I believe Yosry and I have only tested

In my case, both test_progs and test_progs-no_alu32 failed the test.
I think the reason for the failure is the same.

> on test_progs. I tried building and running the no_alu32 version, but
> so far, not able to run test_progs-no_alu32. Whenever I ran
> test_progs-no_alu32, it exits without any message. Do you have any
> clue what could be wrong?

It works fine in my environment. test_progs should be very similar to
test_progs-no_alu32. The only difference is bpf programs with different
insn set. Some tests may not run with test_progs-no_alu32, e.g., newer
atomic insn tests.

I have no idea why test_progs-no_alu32 won't work for you, I guess you 
may need to debug it a little bit.

> 
>>>
> [...]