From a86d695193bfab3f130f9275c275e4e143dcd2e3 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 4 Jul 2025 15:14:08 -0700 Subject: [PATCH] mm/damon: add trace event for effective size quota Aim-oriented DAMOS quota auto-tuning is an important and recommended feature for DAMOS users. Add a trace event for the observability of the tuned quota and tuning itself. [sj@kernel.org: initialize sidx in damos_trace_esz()] Link: https://lkml.kernel.org/r/20250705172003.52324-1-sj@kernel.org [sj@kernel.org: make damos_esz unconditional trace event] Link: https://lkml.kernel.org/r/20250709182843.35812-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250704221408.38510-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: kernel test robot Signed-off-by: Andrew Morton --- include/trace/events/damon.h | 24 ++++++++++++++++++++++++ mm/damon/core.c | 20 +++++++++++++++++++- 2 files changed, 43 insertions(+), 1 deletion(-) diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h index 32c6110760236..852d725afea2f 100644 --- a/include/trace/events/damon.h +++ b/include/trace/events/damon.h @@ -9,6 +9,30 @@ #include #include +TRACE_EVENT(damos_esz, + + TP_PROTO(unsigned int context_idx, unsigned int scheme_idx, + unsigned long esz), + + TP_ARGS(context_idx, scheme_idx, esz), + + TP_STRUCT__entry( + __field(unsigned int, context_idx) + __field(unsigned int, scheme_idx) + __field(unsigned long, esz) + ), + + TP_fast_assign( + __entry->context_idx = context_idx; + __entry->scheme_idx = scheme_idx; + __entry->esz = esz; + ), + + TP_printk("ctx_idx=%u scheme_idx=%u esz=%lu", + __entry->context_idx, __entry->scheme_idx, + __entry->esz) +); + TRACE_EVENT_CONDITION(damos_before_apply, TP_PROTO(unsigned int context_idx, unsigned int scheme_idx, diff --git a/mm/damon/core.c b/mm/damon/core.c index 57a1ace4d10df..e8036254cc987 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2011,12 +2011,26 @@ static void damos_set_effective_quota(struct damos_quota *quota) quota->esz = esz; } +static void damos_trace_esz(struct damon_ctx *c, struct damos *s, + struct damos_quota *quota) +{ + unsigned int cidx = 0, sidx = 0; + struct damos *siter; + + damon_for_each_scheme(siter, c) { + if (siter == s) + break; + sidx++; + } + trace_damos_esz(cidx, sidx, quota->esz); +} + static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) { struct damos_quota *quota = &s->quota; struct damon_target *t; struct damon_region *r; - unsigned long cumulated_sz; + unsigned long cumulated_sz, cached_esz; unsigned int score, max_score = 0; if (!quota->ms && !quota->sz && list_empty("a->goals)) @@ -2030,7 +2044,11 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) quota->total_charged_sz += quota->charged_sz; quota->charged_from = jiffies; quota->charged_sz = 0; + if (trace_damos_esz_enabled()) + cached_esz = quota->esz; damos_set_effective_quota(quota); + if (trace_damos_esz_enabled() && quota->esz != cached_esz) + damos_trace_esz(c, s, quota); } if (!c->ops.get_scheme_score) -- 2.47.2