[LTP] [Query] With THP numa01 - test5() fails

[Jaggi, Manish]

> On 30-Aug-2018, at 6:51 PM, Cyril Hrubis <chrubis@suse.cz> wrote:
> 
> External Email
> 
> Hi!
>> While running LTP test suite with 4.18 kernel ( arm64 ).
>> I see the below failure with THP (Transparent Hugepages) enabled.
>> test5 -  Verification of shared memory interleaved on all nodes
>> 
>> numa01 1 TINFO: The system contains 2 nodes: 0 1
>> numa01 1 TPASS: NUMA local node and memory affinity
>> numa01 2 TPASS: NUMA preferred node policy
>> numa01 3 TPASS: NUMA share memory allocated in preferred node
>> numa01 4 TPASS: NUMA interleave policy
>> numa01 5 TFAIL: NUMA interleave share memory allocated in node1 is less than expected
> 
> There are some problems with the test5. It also fails frequenty if /tmp
> is on btrfs, the problem here is that file based mappings that are
> (faulted) allocated by the filesystem driver do not tend to be
> distributed fully evenly for various reasons (e.g. metadata blocks are
> allocated in batches on btrfs).
> 
> So my guess here would be that THP causes some part(s) of the file, be
> it metadata or the actuall data, backed up by a transparent huge page,
> which causes the pages to be distributed unevely.
> 
> The solution is to take more than one sample and see if data are
> distributed more or less evenly over sum of the samples,

The test randomly passes/fails. I am not sure if THP is related or not.
I see test passing without adding any code with

linux-lr84:/opt/ltp # cat /sys/kernel/mm/transparent_hugepage/enabled
[always] madvise never

> which is what
> I'm working on in replacement for this test that would fix this problem
> along with a few more, see:
> 
> http://lists.linux.it/pipermail/ltp/2018-August/009109.html
> 
> Can try the tests from that patchset to see if these are working fine
> for you?

Getting errors with this patch.

../../../../lib/libltp.a(tst_numa.o): In function `tst_numa_alloc_parse':
/root/ltp/lib/tst_numa.c:78: undefined reference to `get_mempolicy'
../../../../lib/libltp.a(tst_numa.o): In function `tst_get_nodemap':
/root/ltp/lib/tst_numa.c:108: undefined reference to `numa_get_membind'
/root/ltp/lib/tst_numa.c:133: undefined reference to `numa_bitmask_free'
/root/ltp/lib/tst_numa.c:112: undefined reference to `numa_bitmask_isbitset'
/root/ltp/lib/tst_numa.c:127: undefined reference to `numa_bitmask_isbitset'
/root/ltp/lib/tst_numa.c:108: undefined reference to `numa_get_membind'
collect2: error: ld returned 1 exit status
> 
> --
> Cyril Hrubis
> chrubis@suse.cz