Andrew, On 03/11/2023 11:14, Li Zhijian wrote: > Demotion will migrate pages across nodes. Previously, only the global > demotion statistics were accounted for. Changed them to per-node > statistics, making it easier to observe where demotion occurs on each > node. > > This will help to identify which nodes are under pressure. > > This patch also make pgdemote_* behind CONFIG_NUMA_BALANCING, since > demotion is not available for !CONFIG_NUMA_BALANCING I just realized that moving pgdemote_* behind CONFIG_NUMA_BALANCING was wrong. Demotion works well without CONFIG_NUMA_BALANCING. Since this patch was already in the mm-stable branch, is it possible to replace this patch from mm-stable or post a fixup for this Thanks Zhijian > > With this patch, here is a sample where node0 node1 are DRAM, > node3 is PMEM: > Global stats: > $ grep demote /proc/vmstat > pgdemote_kswapd 254288 > pgdemote_direct 113497 > pgdemote_khugepaged 0 > > Per-node stats: > $ grep demote /sys/devices/system/node/node0/vmstat # demotion source > pgdemote_kswapd 68454 > pgdemote_direct 83431 > pgdemote_khugepaged 0 > $ grep demote /sys/devices/system/node/node1/vmstat # demotion source > pgdemote_kswapd 185834 > pgdemote_direct 30066 > pgdemote_khugepaged 0 > $ grep demote /sys/devices/system/node/node3/vmstat # demotion target > pgdemote_kswapd 0 > pgdemote_direct 0 > pgdemote_khugepaged 0 > > Reported-by: kernel test robot <lkp@xxxxxxxxx> # compling errors > Closes: https://lore.kernel.org/oe-kbuild-all/202311030137.Vu2ki6zm-lkp@xxxxxxxxx/ > Acked-by: "Huang, Ying" <ying.huang@xxxxxxxxx> > Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx> > > --- > V2: split it as a separate patch from previous patch set. > account them to the source node instead destination and add Acked-by # Huang, Ying > --- > include/linux/mmzone.h | 4 ++++ > include/linux/vm_event_item.h | 3 --- > mm/vmscan.c | 12 ++++++++---- > mm/vmstat.c | 6 +++--- > 4 files changed, 15 insertions(+), 10 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 4106fbc5b4b3..ad0309eea850 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -206,6 +206,10 @@ enum node_stat_item { > #ifdef CONFIG_NUMA_BALANCING > PGPROMOTE_SUCCESS, /* promote successfully */ > PGPROMOTE_CANDIDATE, /* candidate pages to promote */ > + /* PGDEMOTE_*: pages demoted */ > + PGDEMOTE_KSWAPD, > + PGDEMOTE_DIRECT, > + PGDEMOTE_KHUGEPAGED, > #endif > NR_VM_NODE_STAT_ITEMS > }; > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > index 8abfa1240040..d1b847502f09 100644 > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -41,9 +41,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > PGSTEAL_KSWAPD, > PGSTEAL_DIRECT, > PGSTEAL_KHUGEPAGED, > - PGDEMOTE_KSWAPD, > - PGDEMOTE_DIRECT, > - PGDEMOTE_KHUGEPAGED, > PGSCAN_KSWAPD, > PGSCAN_DIRECT, > PGSCAN_KHUGEPAGED, > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 6f13394b112e..cc70dcefc60a 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1110,12 +1110,14 @@ void drop_slab(void) > > static int reclaimer_offset(void) > { > +#ifdef CONFIG_NUMA_BALANCING > BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD != > PGDEMOTE_DIRECT - PGDEMOTE_KSWAPD); > - BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD != > - PGSCAN_DIRECT - PGSCAN_KSWAPD); > BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD != > PGDEMOTE_KHUGEPAGED - PGDEMOTE_KSWAPD); > +#endif > + BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD != > + PGSCAN_DIRECT - PGSCAN_KSWAPD); > BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD != > PGSCAN_KHUGEPAGED - PGSCAN_KSWAPD); > > @@ -1677,8 +1679,10 @@ static unsigned int demote_folio_list(struct list_head *demote_folios, > migrate_pages(demote_folios, alloc_demote_folio, NULL, > (unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION, > &nr_succeeded); > - > - __count_vm_events(PGDEMOTE_KSWAPD + reclaimer_offset(), nr_succeeded); > +#ifdef CONFIG_NUMA_BALANCING > + mod_node_page_state(pgdat, PGDEMOTE_KSWAPD + reclaimer_offset(), > + nr_succeeded); > +#endif > > return nr_succeeded; > } > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 00e81e99c6ee..f141c48c39e4 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1244,6 +1244,9 @@ const char * const vmstat_text[] = { > #ifdef CONFIG_NUMA_BALANCING > "pgpromote_success", > "pgpromote_candidate", > + "pgdemote_kswapd", > + "pgdemote_direct", > + "pgdemote_khugepaged", > #endif > > /* enum writeback_stat_item counters */ > @@ -1275,9 +1278,6 @@ const char * const vmstat_text[] = { > "pgsteal_kswapd", > "pgsteal_direct", > "pgsteal_khugepaged", > - "pgdemote_kswapd", > - "pgdemote_direct", > - "pgdemote_khugepaged", > "pgscan_kswapd", > "pgscan_direct", > "pgscan_khugepaged",
