[LTP] [PATCH] memcg/memcontrol04: Fix the judgment error in test_memcg_low()

[Jin Guojie]

When I visit https://bugzilla.suse.com/show_bug.cgi?id=1196298, an
error occurs showing that

"You are not authorized to access bug #1196298."

I tried to register an account by myself, but the error did not change.

So far, I still can't view the link.

Please see if there is a way to give me permission to view this bug.

Or, could you please provide me the explanation of this bug in the email？

On Thu, Nov 21, 2024 at 5:44 PM Andrea Cervesato
<andrea.cervesato@suse.com> wrote:
>
> Hi!
>
> Thanks for checking this test, but did you take a look at the
> explanation given in the test "tags" ? ->
> https://bugzilla.suse.com/show_bug.cgi?id=1196298
>
> Regards,
> Andrea
>
> On 11/21/24 04:05, Jin Guojie wrote:
> > When running memcontrol04, TFAIL results will appear on various Linux
> > distributions, kernel versions, and CPUs:
> >
> > (1) Test platform
> >
> > * Linux distribution: Ubuntu 24.10
> > * CPU: X86_64, Arm64
> > * Kernel: 6.6 longterm
> > * glibc:  2.40
> > * LTP version:  commit ec4161186e5, Oct 24 12:18:17 2024
> >
> > (2) Error logs
> >
> > During the operation of memcontrol04, file systems such as ext2, ext3,
> > ext4, xfs, ntfs, and vfat will be tested.
> > For any of the file system, the same TFAIL result will appear:
> >
> > root@vm:~/ltp/testcases/kernel/controllers/memcg# ./memcontrol04
> >
> > tst_test.c:1823: TINFO: === Testing on ext2 ===
> > memcontrol04.c:208: TPASS: Expect: (C oom events=0) == 0
> > memcontrol04.c:211: TPASS: Expect: (C low events=437) > 0
> > memcontrol04.c:208: TPASS: Expect: (D oom events=0) == 0
> > memcontrol04.c:211: TPASS: Expect: (D low events=437) > 0
> > memcontrol04.c:208: TPASS: Expect: (E oom events=0) == 0
> > memcontrol04.c:214: TPASS: Expect: (E low events=0) == 0
> > memcontrol04.c:208: TPASS: Expect: (F oom events=0) == 0
> > memcontrol04.c:214: TFAIL: Expect: (F low events=412) == 0
> >
> > tst_test.c:1823: TINFO: === Testing on ext3 ===
> > memcontrol04.c:208: TPASS: Expect: (C oom events=0) == 0
> > memcontrol04.c:211: TPASS: Expect: (C low events=437) > 0
> > memcontrol04.c:208: TPASS: Expect: (D oom events=0) == 0
> > memcontrol04.c:211: TPASS: Expect: (D low events=437) > 0
> > memcontrol04.c:208: TPASS: Expect: (E oom events=0) == 0
> > memcontrol04.c:214: TPASS: Expect: (E low events=0) == 0
> > memcontrol04.c:208: TPASS: Expect: (F oom events=0) == 0
> > memcontrol04.c:214: TFAIL: Expect: (F low events=411) == 0
> >
> > ......
> >
> > Summary:
> > passed   55
> > failed   5
> > broken   0
> > skipped  0
> > warnings 0
> >
> > It looks like there is an error in the processing logic of cgroup F.
> >
> > (3) Cause analysis
> >
> > In the test_memcg_low() function, 4 subgroups (C, D, E, F) are created under B,
> > and 50MB pagecache is allocated in C, D, and F. Therefore, when checking whether
> > it is successful at the end, only E should be judged to have low_events==0,
> > and the judgment conditions for all other subgroups should be low_events > 0.
> >
> > (4) Fix issure
> >
> > #1209
> > https://github.com/linux-test-project/ltp/issues/1209
> >
> > Signed-off-by: Jin Guojie <guojie.jin@gmail.com>
> >
> > ---
> >   testcases/kernel/controllers/memcg/memcontrol04.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/testcases/kernel/controllers/memcg/memcontrol04.c
> > b/testcases/kernel/controllers/memcg/memcontrol04.c
> > index 1b8d115f8..0dddb7449 100644
> > --- a/testcases/kernel/controllers/memcg/memcontrol04.c
> > +++ b/testcases/kernel/controllers/memcg/memcontrol04.c
> > @@ -207,7 +207,7 @@ static void test_memcg_low(void)
> >
> >                  TST_EXP_EXPR(oom == 0, "(%c oom events=%ld) == 0", id, oom);
> >
> > -               if (i < E) {
> > +               if (i != E) {
> >                          TST_EXP_EXPR(low > 0,
> >                                       "(%c low events=%ld) > 0", id, low);
> >                  } else {
> > --
> > 2.45.2
> >