Re: [PATCH mm-unstable v3 0/4] mm/mglru: Kconfig cleanup

[Donet Tom <donettom@linux.vnet.ibm.com>]

On 12/20/23 09:46, Yu Zhao wrote:
> On Tue, Dec 19, 2023 at 9:01 PM Kinsey Ho <kinseyho@google.com> wrote:
>> This series is the result of the following discussion:
>> https://lore.kernel.org/47066176-bd93-55dd-c2fa-002299d9e034@linux.ibm.com/
>>
>> It mainly avoids building the code that walks page tables on CPUs that
>> use it, i.e., those don't support hardware accessed bit. Specifically,
>> it introduces a new Kconfig to guard some of functions added by
>> commit bd74fdaea146 ("mm: multi-gen LRU: support page table walks")
>> on CPUs like POWER9, on which the series was tested.
>>
>>
>> Kinsey Ho (4):
>>    mm/mglru: add CONFIG_ARCH_HAS_HW_PTE_YOUNG
>>    mm/mglru: add CONFIG_LRU_GEN_WALKS_MMU
>>    mm/mglru: remove CONFIG_MEMCG
>>    mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE
>>
>>   arch/Kconfig                   |   8 +
>>   arch/arm64/Kconfig             |   1 +
>>   arch/x86/Kconfig               |   1 +
>>   arch/x86/include/asm/pgtable.h |   6 -
>>   include/linux/memcontrol.h     |   2 +-
>>   include/linux/mm_types.h       |  16 +-
>>   include/linux/mmzone.h         |  28 +---
>>   include/linux/pgtable.h        |   2 +-
>>   kernel/fork.c                  |   2 +-
>>   mm/Kconfig                     |   4 +
>>   mm/vmscan.c                    | 271 ++++++++++++++++++---------------
>>   11 files changed, 174 insertions(+), 167 deletions(-)
> +Donet Tom <donettom@linux.vnet.ibm.com>
> who is also working on this.
>
> Donet, could try this latest version instead? If it works well as the
> old one you've been using, can you please provide your Tested-by tag?
> Thanks.

Hi Yu Zhao,

This patch set looks promising.

I have conducted tests on PowerPC and x86.

In old patch set there is a cleanup patch which removes
struct scan_control *sc argument from try_to_inc_max_seq() and
run_aging(), Do we need to include that patch?

=>Here are some test results from PowerPC.

# ls -l vmscan.o
-rw-r--r--. 1 root root 3600080 Dec 19 22:35 vmscan.o

# size vmscan.o
   text       data           bss      dec         hex filename
   95086      27412          0        122498      1de82 vmscan.o

# ./scripts/bloat-o-meter vmscan.o.old vmscan.o
add/remove: 4/8 grow/shrink: 7/9 up/down: 860/-2524 (-1664)
Function                              old       new     delta
should_abort_scan                      -        472     +472
inc_max_seq.isra                      1472      1612    +140
shrink_one                            680       760     +80
lru_gen_release_memcg                 508       556     +48
lru_gen_init_pgdat                    92        132     +40
shrink_node                           4040      4064    +24
lru_gen_online_memcg                  680       696     +16
lru_gen_change_state                  3968      3984    +16
------
shrink_lruvec                         2168      2152    -16
lru_gen_seq_write                     1980      1964    -16
isolate_folios                        6904      6888    -16
lru_gen_init_memcg                    32        12      -20
mm_list                               24        -       -24
lru_gen_exit_memcg                    388       344     -44
try_to_shrink_lruvec                  904       816     -88
lru_gen_rotate_memcg                  832       700     -132
lru_gen_migrate_mm                    132       -       -132
lru_gen_seq_show                      1484      1308    -176
iterate_mm_list_nowalk                288       -       -288
lru_gen_look_around                   2284      1984    -300
lru_gen_add_mm                        528       -       -528
lru_gen_del_mm                        720       -       -720
Total: Before=116213, After=114549, chg -1.43%

=>Here are some test results from x86.

$ ls -l vmscan.o
-rw-r--r--. 1 donettom donettom 2545792 Dec 20 15:16 vmscan.o

$ size vmscan.o
   text          data          bss    dec        hex filename
   109751        32189         0      141940     22a74 vmscan.o
$

$ ./scripts/bloat-o-meter vmscan.o.old vmscan.o
add/remove: 7/3 grow/shrink: 14/4 up/down: 2307/-1534 (773)
Function                                old       new      delta
inc_max_seq                             -         1470     +1470
should_abort_scan                       -         229      +229
isolate_folios                          4469      4562     +93
lru_gen_rotate_memcg                    641       731      +90
lru_gen_init_memcg                      41        99       +58
lru_gen_release_memcg                   282       336      +54
lru_gen_exit_memcg                      306       350      +44
walk_pud_range                          2502      2543     +41
shrink_node                             2912      2951     +39
lru_gen_online_memcg                    402       434      +32
lru_gen_seq_show                        1112      1140     +28
lru_gen_add_folio                       740       757      +17
lru_gen_look_around                     1217      1233     +16
__pfx_should_abort_scan                 -         16       +16
__pfx_inc_max_seq                       -         16       +16
iterate_mm_list_nowalk                  277       292      +15
shrink_one                              413       426      +13
lru_gen_init_lruvec                     190       202      +12
-----
try_to_shrink_lruvec                    717       643      -74
lru_gen_init_pgdat                      196       82       -114
try_to_inc_max_seq.isra                 2897      1578     -1319
Total: Before=101095, After=101868, chg +0.76%
$


Tested-by: Donet Tom <donettom@linux.vnet.ibm.com>

Thanks
Donet Tom