From: Ridong Chen <[email protected]> The number of pages of a given type in a generation is computed by summing lrugen->nr_pages[gen][type][] over all zones and clamping each per-zone counter to >= 0, since the counters are updated locklessly and can transiently go negative. This loop is open-coded in lruvec_evictable_size() and in the debugfs lru_gen output.
Add lruvec_gen_size() to compute it from a seq, and convert both users. Put it in mm/vmscan.h so that the vmscan tracepoints, which include that header, can use it as well. An upcoming tracepoint and the MGLRU swappiness rework will also use it. No functional change. Suggested-by: Barry Song <[email protected]> Signed-off-by: Ridong Chen <[email protected]> --- mm/vmscan.c | 18 ++++++------------ mm/vmscan.h | 16 ++++++++++++++++ 2 files changed, 22 insertions(+), 12 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 3054175717ab..1581b73aec56 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4207,18 +4207,15 @@ static void set_initial_priority(struct pglist_data *pgdat, struct scan_control static unsigned long lruvec_evictable_size(struct lruvec *lruvec, int swappiness) { - int gen, type, zone; + int type; unsigned long seq, total = 0; struct lru_gen_folio *lrugen = &lruvec->lrugen; DEFINE_MAX_SEQ(lruvec); DEFINE_MIN_SEQ(lruvec); for_each_evictable_type(type, swappiness) { - for (seq = min_seq[type]; seq <= max_seq; seq++) { - gen = lru_gen_from_seq(seq); - for (zone = 0; zone < MAX_NR_ZONES; zone++) - total += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); - } + for (seq = min_seq[type]; seq <= max_seq; seq++) + total += lruvec_gen_size(lrugen, type, seq); } return total; @@ -5723,20 +5720,17 @@ static int lru_gen_seq_show(struct seq_file *m, void *v) seq = 0; for (; seq <= max_seq; seq++) { - int type, zone; + int type; int gen = lru_gen_from_seq(seq); unsigned long birth = READ_ONCE(lruvec->lrugen.timestamps[gen]); seq_printf(m, " %10lu %10u", seq, jiffies_to_msecs(jiffies - birth)); for (type = 0; type < ANON_AND_FILE; type++) { - unsigned long size = 0; char mark = full && seq < min_seq[type] ? 'x' : ' '; - for (zone = 0; zone < MAX_NR_ZONES; zone++) - size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); - - seq_printf(m, " %10lu%c", size, mark); + seq_printf(m, " %10lu%c", + lruvec_gen_size(lrugen, type, seq), mark); } seq_putc(m, '\n'); diff --git a/mm/vmscan.h b/mm/vmscan.h index adb22e80d760..c6b583fc7493 100644 --- a/mm/vmscan.h +++ b/mm/vmscan.h @@ -3,6 +3,7 @@ #define _MM_VMSCAN_H #include <linux/gfp_types.h> +#include <linux/mm_inline.h> #include <linux/nodemask.h> #include <linux/swap.h> #include <linux/types.h> @@ -115,4 +116,19 @@ struct scan_control { struct reclaim_state reclaim_state; }; +#ifdef CONFIG_LRU_GEN +/* The number of pages of @type in the generation @seq, summed over all zones */ +static inline unsigned long lruvec_gen_size(struct lru_gen_folio *lrugen, + int type, unsigned long seq) +{ + int gen = lru_gen_from_seq(seq); + unsigned long size = 0; + + for (int zone = 0; zone < MAX_NR_ZONES; zone++) + size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); + + return size; +} +#endif /* CONFIG_LRU_GEN */ + #endif /* _MM_VMSCAN_H */ -- 2.34.1
