From: Ridong Chen <[email protected]> MGLRU's scan_folios() and evict_folios() emit the classic-LRU tracepoints trace_mm_vmscan_lru_isolate() and trace_mm_vmscan_lru_shrink_inactive(). Those predate MGLRU and are indistinguishable from the classic-LRU path: they carry no generation, sequence, memcg or swappiness context, so a trace of an MGLRU run cannot tell which memcg a given scan/evict belongs to, nor how far reclaim has progressed through the generations.
Add mm_mglru_isolate_folios, emitted once per isolate_folios() call with the memcg id, the type actually scanned, the effective swappiness, the scanned/isolated counts, and the anon/file min_seq and max_seq. The min_seq/max_seq triplet ties each isolation to the generation layout it ran against, which the classic-LRU tracepoints cannot express. This is emitted at the isolate_folios() layer, which is MGLRU-specific and has no classic-LRU counterpart, so it neither changes nor duplicates the existing scan/evict tracepoints. Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Ridong Chen <[email protected]> --- include/trace/events/vmscan.h | 47 +++++++++++++++++++++++++++++++++++ mm/vmscan.c | 9 ++++++- 2 files changed, 55 insertions(+), 1 deletion(-) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 8a872990b4be..a0e3cf75294b 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -392,6 +392,53 @@ TRACE_EVENT(mm_vmscan_lru_isolate, __print_symbolic(__entry->lru, LRU_NAMES)) ); +TRACE_EVENT(mm_mglru_isolate_folios, + + TP_PROTO(u64 memcg_id, + int type, + int swappiness, + unsigned long nr_scanned, + unsigned long nr_isolated, + unsigned long anon_min_seq, + unsigned long file_min_seq, + unsigned long max_seq), + + TP_ARGS(memcg_id, type, swappiness, nr_scanned, nr_isolated, + anon_min_seq, file_min_seq, max_seq), + + TP_STRUCT__entry( + __field(u64, memcg_id) + __field(int, type) + __field(int, swappiness) + __field(unsigned long, nr_scanned) + __field(unsigned long, nr_isolated) + __field(unsigned long, anon_min_seq) + __field(unsigned long, file_min_seq) + __field(unsigned long, max_seq) + ), + + TP_fast_assign( + __entry->memcg_id = memcg_id; + __entry->type = type; + __entry->swappiness = swappiness; + __entry->nr_scanned = nr_scanned; + __entry->nr_isolated = nr_isolated; + __entry->anon_min_seq = anon_min_seq; + __entry->file_min_seq = file_min_seq; + __entry->max_seq = max_seq; + ), + + TP_printk("memcg_id=%llu type=%s swappiness=%d nr_scanned=%lu nr_isolated=%lu anon_min_seq=%lu file_min_seq=%lu max_seq=%lu", + __entry->memcg_id, + __entry->type ? "file" : "anon", + __entry->swappiness, + __entry->nr_scanned, + __entry->nr_isolated, + __entry->anon_min_seq, + __entry->file_min_seq, + __entry->max_seq) +); + TRACE_EVENT(mm_vmscan_write_folio, TP_PROTO(struct folio *folio), diff --git a/mm/vmscan.c b/mm/vmscan.c index 8409ea4bbf37..771fe6827939 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4843,6 +4843,7 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, bool type_fallback_allowed = !is_single_type_reclaim(swappiness); int type = get_type_to_scan(lruvec, swappiness); int total_scanned = 0, scanned, tier; + struct lru_gen_folio *lrugen = &lruvec->lrugen; bool tried = false; retry: @@ -4854,7 +4855,7 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, if (*isolated) { *isolate_type = type; *isolate_scanned = scanned; - return total_scanned; + goto done; } /* @@ -4876,6 +4877,12 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, goto retry; } +done: + trace_mm_mglru_isolate_folios(mem_cgroup_id(lruvec_memcg(lruvec)), + type, swappiness, total_scanned, *isolated, + lrugen->min_seq[LRU_GEN_ANON], + lrugen->min_seq[LRU_GEN_FILE], + lrugen->max_seq); return total_scanned; } -- 2.34.1
