[LTP] [PATCH] move_pages12: compacting memory before each test loop

[Li Wang]

Hi Petr,

On Thu, Feb 22, 2024 at 12:28 AM Petr Vorel <pvorel@suse.cz> wrote:

> Hi Li,
>
> > These simple steps are added to prepare the system's memory state
> > for the test, aiming to increase the test's reliability and
> > consistency by starting from a clean and defragmented memory state.
>
> > To reduce accidental failures on small (1.5G) RAM system:
>
> >   7 tst_test.c:1558: TINFO: Timeout per run is 0h 21m 00s
> >   8 move_pages12.c:273: TINFO: Free RAM 1542656 kB
> >   9 move_pages12.c:289: TINFO: Increasing 16384kB hugepages pool on node
> 0 to 4
> >   10 move_pages12.c:299: TINFO: Increasing 16384kB hugepages pool on
> node 1 to 4
> >   11 move_pages12.c:216: TINFO: Allocating and freeing 4 hugepages on
> node 0
> >   12 move_pages12.c:216: TINFO: Allocating and freeing 4 hugepages on
> node 1
> >   13 move_pages12.c:207: TPASS: Bug not reproduced
> >   14 move_pages12.c:106: TFAIL: madvise failed: ENOMEM (12)
> >   ...<repeats 741 times>...
> >   756 move_pages12.c:207: TPASS: Bug not reproduced
>
> > Note:
> >   This is a single hugetlb test without invoking the hugetlb-lib of LTP,
> >   so we add the compacting memory/cache steps additionally.
>
> > Signed-off-by: Li Wang <liwang@redhat.com>
> > ---
> >  testcases/kernel/syscalls/move_pages/move_pages12.c | 3 +++
> >  1 file changed, 3 insertions(+)
>
> > diff --git a/testcases/kernel/syscalls/move_pages/move_pages12.c
> b/testcases/kernel/syscalls/move_pages/move_pages12.c
> > index fd7017d79..c387a326f 100644
> > --- a/testcases/kernel/syscalls/move_pages/move_pages12.c
> > +++ b/testcases/kernel/syscalls/move_pages/move_pages12.c
> > @@ -154,6 +154,9 @@ static void do_test(unsigned int n)
> >       pid_t cpid = -1;
> >       int status;
>
> > +     SAFE_FILE_PRINTF("/proc/sys/vm/drop_caches", "3");
> > +     SAFE_FILE_PRINTF("/proc/sys/vm/compact_memory", "1");
>
> LGTM
> Reviewed-by: Petr Vorel <pvorel@suse.cz>
>
> BTW we clear cache with /proc/sys/vm/drop_caches in quite a few files,
> I wonder if it would make sense to add a helper for it. Likely not
> (it's oneliner).
>

Hmm yes, maybe better put the drop caches in the setup function,
at least release more free-mem for comparison.


# free -h
               total        used        free      shared  buff/cache
available
Mem:            15Gi       5.1Gi       2.3Gi        17Mi       8.1Gi
 10Gi
Swap:           11Gi       2.1Gi       9.9Gi

# echo 3 >/proc/sys/vm/drop_caches

# free -h
               total        used        free      shared  buff/cache
available
Mem:            15Gi       4.9Gi        10Gi        17Mi       351Mi
 10Gi
Swap:           11Gi       2.1Gi       9.9Gi



>
> Kind regards,
> Petr
>
> > +
> >       addr = SAFE_MMAP(NULL, tcases[n].tpages * hpsz, PROT_READ |
> PROT_WRITE,
> >               MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
>
>
Pushed with minor adjustments in the order.


-- 
Regards,
Li Wang