Subject: [bug report & help] arm64: ltp testcase "migrate_pages01" failed

From: [email-masked] (Tan Xiaojun)
Date: Mon, 16 Oct 2017 19:42:35 +0800

Hi all,

I test ltp in Hisilicon D05 board and get a failed result about the testcase "migrate_pages01".

In fact, The sub testcase "test_invalid_nodes" failed. The testcase is to find a invalid numa node and migrate memory pages to this node via syscall of "migrate_pages".
The expected result of this case is returning "-1", but it actually return "0".

--------------------------------------------------------
# ./migrate_pages01
migrate_pages01    0  TINFO  :  test_empty_mask
migrate_pages01    1  TPASS  :  expected ret success: returned value = 0
migrate_pages01    0  TINFO  :  test_invalid_pid -1
migrate_pages01    2  TPASS  :  expected ret success: returned value = -1
migrate_pages01    3  TPASS  :  expected failure: TEST_ERRNO=ESRCH(3): No such process
migrate_pages01    0  TINFO  :  test_invalid_pid unused pid
migrate_pages01    4  TPASS  :  expected ret success: returned value = -1
migrate_pages01    5  TPASS  :  expected failure: TEST_ERRNO=ESRCH(3): No such process
migrate_pages01    0  TINFO  :  test_invalid_masksize
migrate_pages01    6  TPASS  :  expected ret success: returned value = -1
migrate_pages01    7  TPASS  :  expected failure: TEST_ERRNO=EINVAL(22): Invalid argument
migrate_pages01    0  TINFO  :  test_invalid_mem -1
migrate_pages01    8  TPASS  :  expected ret success: returned value = -1
migrate_pages01    9  TPASS  :  expected failure: TEST_ERRNO=EFAULT(14): Bad address
migrate_pages01    0  TINFO  :  test_invalid_mem invalid prot
migrate_pages01   10  TPASS  :  expected ret success: returned value = -1
migrate_pages01   11  TPASS  :  expected failure: TEST_ERRNO=EFAULT(14): Bad address
migrate_pages01    0  TINFO  :  test_invalid_mem unmmaped
migrate_pages01   12  TPASS  :  expected ret success: returned value = -1
migrate_pages01   13  TPASS  :  expected failure: TEST_ERRNO=EFAULT(14): Bad address
migrate_pages01    0  TINFO  :  test_invalid_nodes
migrate_pages01   14  TFAIL  :  migrate_pages_common.c:45: unexpected failure - returned value = 0, expected: -1
migrate_pages01   15  TFAIL  :  migrate_pages_common.c:55: call succeeded unexpectedly
migrate_pages01    0  TINFO  :  test_invalid_perm
migrate_pages01   16  TPASS  :  expected ret success: returned value = -1
migrate_pages01   17  TPASS  :  expected failure: TEST_ERRNO=EPERM(1): Operation not permitted
--------------------------------------------------------

I debug and find a interesting thing, this case does not always fail.

1) If one or several numa nodes have no memory, this case will run successfully like below:

--------------------
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
node 0 size: 65309 MB
node 0 free: 61650 MB
node 1 cpus: 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
node 1 size: 65404 MB
node 1 free: 61377 MB
node 2 cpus: 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
node 2 size: 65401 MB
node 2 free: 62316 MB
node 3 cpus: 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
node 3 size: 0 MB
node 3 free: 0 MB
node distances:
node   0   1   2   3
  0:  10  15  20  20
  1:  15  10  20  20
  2:  20  20  10  15
  3:  20  20  15  10
---------------------

This testcase will find node number 3 and migrate pages to node 3. And syscall of "migrate_pages" return -1, test succeeded.

2) In most cases, all nodes have memory, and the testcase will get non-existent node like node number 4. The syscall of "migrate_pages" should also return -1, but return 0 actually.
So the testcase failed.

I think it is a problem in arm64. But I am not familiar with numa, so I ask for help from you.

Thanks.
Xiaojun.