From 89fca4f446aea83c1de4b9eac6750ecb3bdd1ab0 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 23 Apr 2026 06:01:08 -0500
Subject: [PATCH] merge

---
 .../runtime_stats/runtime_stats.cpp           | 21 +++++++++++++++++++
 .../components/runtime_stats/runtime_stats.h  | 12 ++++++++++-
 esphome/core/application.cpp                  |  3 +++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/esphome/components/runtime_stats/runtime_stats.cpp b/esphome/components/runtime_stats/runtime_stats.cpp
index d733394b78..26571a4054 100644
--- a/esphome/components/runtime_stats/runtime_stats.cpp
+++ b/esphome/components/runtime_stats/runtime_stats.cpp
@@ -81,6 +81,19 @@ void RuntimeStatsCollector::log_stats_() {
     ESP_LOGI(TAG, "  main_loop_overhead_section: before=%.1fms, tail=%.1fms, inter_component=%.1fms",
              static_cast<double>(before) / 1000.0, static_cast<double>(tail) / 1000.0,
              static_cast<double>(inter) / 1000.0);
+    uint64_t sched = this->period_before_sched_time_us_;
+    uint64_t wdt = this->period_before_wdt_time_us_;
+    uint64_t before_residual = before > sched + wdt ? before - sched - wdt : 0;
+    ESP_LOGI(TAG, "  main_loop_before_breakdown: sched=%.1fms, wdt=%.1fms, residual=%.1fms",
+             static_cast<double>(sched) / 1000.0, static_cast<double>(wdt) / 1000.0,
+             static_cast<double>(before_residual) / 1000.0);
+    uint32_t wdt_slow_hits = App.wdt_slow_count_;
+    App.wdt_slow_count_ = 0;
+    ESP_LOGI(TAG, "  wdt_slow_path: hits=%" PRIu32 " (%.1f%% of iters, avg=%.2fus/hit)", wdt_slow_hits,
+             this->period_active_count_ > 0
+                 ? 100.0 * static_cast<double>(wdt_slow_hits) / static_cast<double>(this->period_active_count_)
+                 : 0.0,
+             wdt_slow_hits > 0 ? static_cast<double>(wdt) / static_cast<double>(wdt_slow_hits) : 0.0);
   }
 
   // Log total stats since boot (only for active components - idle ones haven't changed)
@@ -116,6 +129,12 @@ void RuntimeStatsCollector::log_stats_() {
     ESP_LOGI(TAG, "  main_loop_overhead_section: before=%.1fms, tail=%.1fms, inter_component=%.1fms",
              static_cast<double>(before) / 1000.0, static_cast<double>(tail) / 1000.0,
              static_cast<double>(inter) / 1000.0);
+    uint64_t sched = this->total_before_sched_time_us_;
+    uint64_t wdt = this->total_before_wdt_time_us_;
+    uint64_t before_residual = before > sched + wdt ? before - sched - wdt : 0;
+    ESP_LOGI(TAG, "  main_loop_before_breakdown: sched=%.1fms, wdt=%.1fms, residual=%.1fms",
+             static_cast<double>(sched) / 1000.0, static_cast<double>(wdt) / 1000.0,
+             static_cast<double>(before_residual) / 1000.0);
   }
 
   // Reset period stats
@@ -126,6 +145,8 @@ void RuntimeStatsCollector::log_stats_() {
   this->period_active_time_us_ = 0;
   this->period_active_max_us_ = 0;
   this->period_before_time_us_ = 0;
+  this->period_before_sched_time_us_ = 0;
+  this->period_before_wdt_time_us_ = 0;
   this->period_tail_time_us_ = 0;
 }
 
diff --git a/esphome/components/runtime_stats/runtime_stats.h b/esphome/components/runtime_stats/runtime_stats.h
index 888d48e672..68409fbbfe 100644
--- a/esphome/components/runtime_stats/runtime_stats.h
+++ b/esphome/components/runtime_stats/runtime_stats.h
@@ -49,7 +49,8 @@ class RuntimeStatsCollector {
   // which captures per-iteration inter-component bookkeeping (set_current_component,
   // WarnIfComponentBlockingGuard construction/destruction, feed_wdt_with_time calls,
   // the for-loop itself).
-  void record_loop_active(uint32_t active_us, uint32_t before_us, uint32_t tail_us) {
+  void record_loop_active(uint32_t active_us, uint32_t before_us, uint32_t sched_us, uint32_t wdt_us,
+                          uint32_t tail_us) {
     this->period_active_count_++;
     this->period_active_time_us_ += active_us;
     if (active_us > this->period_active_max_us_)
@@ -61,6 +62,10 @@ class RuntimeStatsCollector {
 
     this->period_before_time_us_ += before_us;
     this->total_before_time_us_ += before_us;
+    this->period_before_sched_time_us_ += sched_us;
+    this->total_before_sched_time_us_ += sched_us;
+    this->period_before_wdt_time_us_ += wdt_us;
+    this->total_before_wdt_time_us_ += wdt_us;
     this->period_tail_time_us_ += tail_us;
     this->total_tail_time_us_ += tail_us;
   }
@@ -88,6 +93,11 @@ class RuntimeStatsCollector {
   // Split of overhead sections — accumulated per iteration.
   uint64_t period_before_time_us_{0};
   uint64_t total_before_time_us_{0};
+  // Sub-split of `before` into scheduler_tick_ vs. post-scheduler feed_wdt_with_time.
+  uint64_t period_before_sched_time_us_{0};
+  uint64_t total_before_sched_time_us_{0};
+  uint64_t period_before_wdt_time_us_{0};
+  uint64_t total_before_wdt_time_us_{0};
   uint64_t period_tail_time_us_{0};
   uint64_t total_tail_time_us_{0};
 };
diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp
index d03696fbb6..c390b26cd4 100644
--- a/esphome/core/application.cpp
+++ b/esphome/core/application.cpp
@@ -210,6 +210,9 @@ void HOT Application::feed_wdt_slow_(uint32_t time) {
   // confirmed the WDT_FEED_INTERVAL_MS rate limit was exceeded.
   arch_feed_wdt();
   this->last_wdt_feed_ = time;
+#ifdef USE_RUNTIME_STATS
+  this->wdt_slow_count_++;
+#endif
 }
 
 #ifdef USE_STATUS_LED