- cost_tracker is data member of a bank, it can report metrics when bank is frozen (#20802)

- removed cost_tracker_stats and histogram
- move stats reporting outside of bank freeze

core/src/cost_update_service.rs

@@ -5,7 +5,7 @@
 
 use solana_ledger::blockstore::Blockstore;
 use solana_measure::measure::Measure;
-use solana_runtime::{bank::ExecuteTimings, cost_model::CostModel};
+use solana_runtime::{bank::Bank, bank::ExecuteTimings, cost_model::CostModel};
 use solana_sdk::timing::timestamp;
 use std::{
     sync::{
@@ -65,7 +65,12 @@ impl CostUpdateServiceTiming {
     }
 }
 
-pub type CostUpdateReceiver = Receiver<ExecuteTimings>;
+pub enum CostUpdate {
+    FrozenBank { bank: Arc<Bank> },
+    ExecuteTiming { execute_timings: ExecuteTimings },
+}
+
+pub type CostUpdateReceiver = Receiver<CostUpdate>;
 
 pub struct CostUpdateService {
     thread_hdl: JoinHandle<()>,
@@ -113,8 +118,15 @@ impl CostUpdateService {
             update_count = 0_u64;
             let mut update_cost_model_time = Measure::start("update_cost_model_time");
             for cost_update in cost_update_receiver.try_iter() {
-                dirty |= Self::update_cost_model(&cost_model, &cost_update);
-                update_count += 1;
+                match cost_update {
+                    CostUpdate::FrozenBank { bank } => {
+                        bank.read_cost_tracker().unwrap().report_stats(bank.slot());
+                    }
+                    CostUpdate::ExecuteTiming { execute_timings } => {
+                        dirty |= Self::update_cost_model(&cost_model, &execute_timings);
+                        update_count += 1;
+                    }
+                }
             }
             update_cost_model_time.stop();