Commit 1f2d03cc authored by Jaewon Kim's avatar Jaewon Kim Committed by Andrew Morton
Browse files

vmscan: add a vmscan event for reclaim_pages 

reclaim_folio_list uses a dummy reclaim_stat and is not being used.  To
know the memory stat, add a new trace event.  This is useful how how many
pages are not reclaimed or why.

This is an example:

mm_vmscan_reclaim_pages: nid=0 nr_scanned=112 nr_reclaimed=112 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0

Currently reclaim_folio_list is only called by reclaim_pages, and
reclaim_pages is used by damon and madvise.  In the latest Android,
reclaim_pages is also used by shmem to reclaim all pages in a
address_space.

[jaewon31.kim@samsung.com: use sc.nr_scanned rather than new counting]
  Link: https://lkml.kernel.org/r/20241016143227.961162-1-jaewon31.kim@samsung.com
Link: https://lkml.kernel.org/r/20241011124928.1224813-1-jaewon31.kim@samsung.com


Signed-off-by: default avatarJaewon Kim <jaewon31.kim@samsung.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 5708d96d

include/trace/events/vmscan.h

+45 −0
Original line number Diff line number Diff line
@@ -346,6 +346,51 @@ TRACE_EVENT(mm_vmscan_write_folio, 
		show_reclaim_flags(__entry->reclaim_flags))

);



TRACE_EVENT(mm_vmscan_reclaim_pages,



	TP_PROTO(int nid,

		unsigned long nr_scanned, unsigned long nr_reclaimed,

		struct reclaim_stat *stat),



	TP_ARGS(nid, nr_scanned, nr_reclaimed, stat),



	TP_STRUCT__entry(

		__field(int, nid)

		__field(unsigned long, nr_scanned)

		__field(unsigned long, nr_reclaimed)

		__field(unsigned long, nr_dirty)

		__field(unsigned long, nr_writeback)

		__field(unsigned long, nr_congested)

		__field(unsigned long, nr_immediate)

		__field(unsigned int, nr_activate0)

		__field(unsigned int, nr_activate1)

		__field(unsigned long, nr_ref_keep)

		__field(unsigned long, nr_unmap_fail)

	),



	TP_fast_assign(

		__entry->nid = nid;

		__entry->nr_scanned = nr_scanned;

		__entry->nr_reclaimed = nr_reclaimed;

		__entry->nr_dirty = stat->nr_dirty;

		__entry->nr_writeback = stat->nr_writeback;

		__entry->nr_congested = stat->nr_congested;

		__entry->nr_immediate = stat->nr_immediate;

		__entry->nr_activate0 = stat->nr_activate[0];

		__entry->nr_activate1 = stat->nr_activate[1];

		__entry->nr_ref_keep = stat->nr_ref_keep;

		__entry->nr_unmap_fail = stat->nr_unmap_fail;

	),



	TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld",

		__entry->nid,

		__entry->nr_scanned, __entry->nr_reclaimed,

		__entry->nr_dirty, __entry->nr_writeback,

		__entry->nr_congested, __entry->nr_immediate,

		__entry->nr_activate0, __entry->nr_activate1,

		__entry->nr_ref_keep, __entry->nr_unmap_fail)

);



TRACE_EVENT(mm_vmscan_lru_shrink_inactive,



	TP_PROTO(int nid,

mm/vmscan.c

+3 −2
Original line number Diff line number Diff line
@@ -2129,7 +2129,7 @@ static void shrink_active_list(unsigned long nr_to_scan, 
static unsigned int reclaim_folio_list(struct list_head *folio_list,

				      struct pglist_data *pgdat)

{

	struct reclaim_stat dummy_stat;

	struct reclaim_stat stat;

	unsigned int nr_reclaimed;

	struct folio *folio;

	struct scan_control sc = {
@@ -2140,12 +2140,13 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, 
		.no_demotion = 1,

	};



	nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true);

	nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &stat, true);

	while (!list_empty(folio_list)) {

		folio = lru_to_folio(folio_list);

		list_del(&folio->lru);

		folio_putback_lru(folio);

	}

	trace_mm_vmscan_reclaim_pages(pgdat->node_id, sc.nr_scanned, nr_reclaimed, &stat);



	return nr_reclaimed;

}