@@ -1053,7 +1053,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
struct folio_batch free_folios;
LIST_HEAD(ret_folios);
LIST_HEAD(demote_folios);
- unsigned int nr_reclaimed = 0;
+ unsigned int nr_reclaimed = 0, nr_demoted = 0;
unsigned int pgactivate = 0;
bool do_demote_pass;
struct swap_iocb *plug = NULL;
@@ -1522,8 +1522,9 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
/* 'folio_list' is always empty here */
/* Migrate folios selected for demotion */
- stat->nr_demoted = demote_folio_list(&demote_folios, pgdat);
- nr_reclaimed += stat->nr_demoted;
+ nr_demoted = demote_folio_list(&demote_folios, pgdat);
+ nr_reclaimed += nr_demoted;
+ stat->nr_demoted += nr_demoted;
/* Folios that could not be demoted are still in @demote_folios */
if (!list_empty(&demote_folios)) {
/* Folios which weren't demoted go back on @folio_list */
In the shrink_folio_list() function, demote_folio_list() can be called 2 times. Currently stat->nr_demoted will only store the last nr_demoted( the later nr_demoted is always zero, the former nr_demoted will get lost), as a result number of demoted pages is not accurate. Accumulate the nr_demoted count across multiple calls to demote_folio_list(), ensuring accurate reporting of demotion statistics. Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- Cc: Kaiyang Zhao <kaiyang2@cs.cmu.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Kaiyang, I removed you ACKED tag for V1, please review again Andrew, Please drop the v1 from the mm-hotfixs-unstable if V2 is accepted. V2: Introudce a local nr_demoted to fix it's counted 2 times by nr_reclaimed wrongly. --- mm/vmscan.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)