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authorLi Zhijian <lizhijian@fujitsu.com>2025-01-10 20:21:32 +0800
committerAndrew Morton <akpm@linux-foundation.org>2025-02-01 03:53:24 -0800
commita479b078fddb0ad7f9e3c6da22d9cf8f2b5c7799 (patch)
treebfec2c979a20b2f9d66e9e37ba1b5e14ccf9fa26 /mm/vmscan.c
parentf921da2c34692dfec5f72b5ae347b1bea22bb369 (diff)
mm/vmscan: accumulate nr_demoted for accurate demotion statistics
In shrink_folio_list(), 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. [lizhijian@fujitsu.com: introduce local nr_demoted to fix nr_reclaimed double counting] Link: https://lkml.kernel.org/r/20250111015253.425693-1-lizhijian@fujitsu.com Link: https://lkml.kernel.org/r/20250110122133.423481-1-lizhijian@fujitsu.com Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Acked-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu> Tested-by: Donet Tom <donettom@linux.ibm.com> Reviewed-by: Donet Tom <donettom@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5b2f12425b28..c767d71c43d7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1086,7 +1086,7 @@ 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;
@@ -1550,8 +1550,9 @@ keep:
/* '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 */