On Tue, 12 May 2026 07:36:33 -0700 SeongJae Park <[email protected]> wrote:
> Introduce a new tracepoint for exposing the per-region per-probe > positive sample count via tracefs. > > Signed-off-by: SeongJae Park <[email protected]> > --- > include/trace/events/damon.h | 36 ++++++++++++++++++++++++++++++++++++ > mm/damon/core.c | 7 +++++++ > 2 files changed, 43 insertions(+) > > diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h > index 7e25f4469b81b..d7b94c7640217 100644 > --- a/include/trace/events/damon.h > +++ b/include/trace/events/damon.h > @@ -130,6 +130,42 @@ TRACE_EVENT(damon_monitor_intervals_tune, > TP_printk("sample_us=%lu", __entry->sample_us) > ); > > +TRACE_EVENT(damon_aggregated_v2, > + > + TP_PROTO(unsigned int target_id, struct damon_region *r, > + unsigned int nr_regions, unsigned int nr_probes), > + > + TP_ARGS(target_id, r, nr_regions, nr_probes), > + > + TP_STRUCT__entry( > + __field(unsigned long, target_id) > + __field(unsigned long, start) > + __field(unsigned long, end) > + __field(unsigned int, nr_regions) > + __field(unsigned int, nr_accesses) > + __field(unsigned int, age) > + __dynamic_array(unsigned char, probe_hits, nr_probes) > + ), > + > + TP_fast_assign( > + __entry->target_id = target_id; > + __entry->start = r->ar.start; > + __entry->end = r->ar.end; > + __entry->nr_regions = nr_regions; > + __entry->nr_accesses = r->nr_accesses; > + __entry->age = r->age; > + memcpy(__get_dynamic_array(probe_hits), r->probe_hits, > + sizeof(*r->probe_hits) * nr_probes); > + ), > + > + TP_printk("target_id=%lu nr_regions=%u %lu-%lu: %u %u probe_hits=%s", > + __entry->target_id, __entry->nr_regions, > + __entry->start, __entry->end, > + __entry->nr_accesses, __entry->age, > + __print_hex(__get_dynamic_array(probe_hits), > + __get_dynamic_array_len(probe_hits))) > +); > + > TRACE_EVENT(damon_aggregated, > > TP_PROTO(unsigned int target_id, struct damon_region *r, > diff --git a/mm/damon/core.c b/mm/damon/core.c > index fe6c789f2cecb..14b15c9876516 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -1905,6 +1905,11 @@ static void kdamond_reset_aggregated(struct damon_ctx > *c) > { > struct damon_target *t; > unsigned int ti = 0; /* target's index */ > + unsigned int nr_probes = 0; > + struct damon_probe *probe; > + > + damon_for_each_probe(probe, c) > + nr_probes++; Is the above logic needed when the tracepoint isn't enabled? If not, then you could add: if (trace_damon_aggregated_v2_enabled()) { damon_for_each_probe(probe, c) nr_probes++; } And change the tracepoint to be a conditional tracepoint: TRACE_EVENT_CONDITION(damon_aggregated_v2, TP_PROTO(..), TP_ARGS(..), TP_CONDITION(nr_probes > 0), [..] And then the tracepoint is only triggered if nr_probes is greater than zero (to handle races between the tracepoint being enabled in between the above check and where it triggers). -- Steve > > damon_for_each_target(t, c) { > struct damon_region *r; > @@ -1913,6 +1918,8 @@ static void kdamond_reset_aggregated(struct damon_ctx > *c) > int i; > > trace_damon_aggregated(ti, r, damon_nr_regions(t)); > + trace_damon_aggregated_v2(ti, r, damon_nr_regions(t), > + nr_probes); > damon_warn_fix_nr_accesses_corruption(r); > r->last_nr_accesses = r->nr_accesses; > r->nr_accesses = 0;
