| Message ID | 20250109060540.451261-1-donettom@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: vmscan : pgdemote vmstat is not getting updated when MGLRU is enabled. | expand |
On Wed, Jan 8, 2025 at 11:05 PM Donet Tom <donettom@linux.ibm.com> wrote: > > When MGLRU is enabled, the pgdemote_kswapd, pgdemote_direct, and > pgdemote_khugepaged stats in vmstat are not being updated. > > 'Commit f77f0c751478 ("mm,memcg: provide per-cgroup counters for > NUMA balancing operations")' moved the pgdemote vmstat update > from demote_folio_list() to shrink_inactive_list(), which is in > the normal LRU path. As a result, the pgdemote stats are updated > correctly for the normal LRU but not for MGLRU. > > To address this, we have added the pgdemote stat update in the > evict_folios() function, which is in the MGLRU path. With this > patch, the pgdemote stats will now be updated correctly when MGLRU > is enabled. > > Without this patch vmstat output when MGLRU is enabled > ====================================================== > pgdemote_kswapd 0 > pgdemote_direct 0 > pgdemote_khugepaged 0 > > With this patch vmstat output when MGLRU is enabled > =================================================== > pgdemote_kswapd 43234 > pgdemote_direct 4691 > pgdemote_khugepaged 0 > > Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations") > Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: Yu Zhao <yuzhao@google.com>
diff --git a/mm/vmscan.c b/mm/vmscan.c index 9a859b7d18d7..b1ec5ece067e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4642,6 +4642,9 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap reset_batch_size(walk); } + __mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(), + stat.nr_demoted); + item = PGSTEAL_KSWAPD + reclaimer_offset(); if (!cgroup_reclaim(sc)) __count_vm_events(item, reclaimed);
When MGLRU is enabled, the pgdemote_kswapd, pgdemote_direct, and pgdemote_khugepaged stats in vmstat are not being updated. 'Commit f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations")' moved the pgdemote vmstat update from demote_folio_list() to shrink_inactive_list(), which is in the normal LRU path. As a result, the pgdemote stats are updated correctly for the normal LRU but not for MGLRU. To address this, we have added the pgdemote stat update in the evict_folios() function, which is in the MGLRU path. With this patch, the pgdemote stats will now be updated correctly when MGLRU is enabled. Without this patch vmstat output when MGLRU is enabled ====================================================== pgdemote_kswapd 0 pgdemote_direct 0 pgdemote_khugepaged 0 With this patch vmstat output when MGLRU is enabled =================================================== pgdemote_kswapd 43234 pgdemote_direct 4691 pgdemote_khugepaged 0 Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations") Signed-off-by: Donet Tom <donettom@linux.ibm.com> --- mm/vmscan.c | 3 +++ 1 file changed, 3 insertions(+)