Revert "Add bank drop service (#21322) (#21360)"

This reverts commit b030d4be7c.

core/src/consensus.rs

@@ -1548,7 +1548,6 @@ pub mod test {
         }
 
         pub fn set_root(&mut self, new_root: Slot) {
-            let (bank_drop_sender, _bank_drop_receiver) = std::sync::mpsc::channel();
             ReplayStage::handle_new_root(
                 new_root,
                 &self.bank_forks,
@@ -1561,7 +1560,6 @@ pub mod test {
                 &mut UnfrozenGossipVerifiedVoteHashes::default(),
                 &mut true,
                 &mut Vec::new(),
-                &bank_drop_sender,
             )
         }
 

core/src/drop_bank_service.rs

@@ -1,38 +0,0 @@
-use solana_measure::measure::Measure;
-use solana_runtime::bank::Bank;
-use std::{
-    sync::{mpsc::Receiver, Arc},
-    thread::{self, Builder, JoinHandle},
-};
-
-pub struct DropBankService {
-    thread_hdl: JoinHandle<()>,
-}
-
-impl DropBankService {
-    pub fn new(bank_receiver: Receiver<Vec<Arc<Bank>>>) -> Self {
-        let thread_hdl = Builder::new()
-            .name("sol-drop-b-service".to_string())
-            .spawn(move || {
-                for banks in bank_receiver.iter() {
-                    let len = banks.len();
-                    let mut dropped_banks_time = Measure::start("drop_banks");
-                    drop(banks);
-                    dropped_banks_time.stop();
-                    if dropped_banks_time.as_ms() > 10 {
-                        datapoint_info!(
-                            "handle_new_root-dropped_banks",
-                            ("elapsed_ms", dropped_banks_time.as_ms(), i64),
-                            ("len", len, i64)
-                        );
-                    }
-                }
-            })
-            .unwrap();
-        Self { thread_hdl }
-    }
-
-    pub fn join(self) -> thread::Result<()> {
-        self.thread_hdl.join()
-    }
-}

core/src/lib.rs

@@ -20,7 +20,6 @@ pub mod commitment_service;
 pub mod completed_data_sets_service;
 pub mod consensus;
 pub mod cost_update_service;
-pub mod drop_bank_service;
 pub mod fetch_stage;
 pub mod fork_choice;
 pub mod gen_keys;

core/src/replay_stage.rs

@@ -316,7 +316,6 @@ impl ReplayStage {
         cluster_slots_update_sender: ClusterSlotsUpdateSender,
         voting_sender: Sender<VoteOp>,
         cost_update_sender: Sender<CostUpdate>,
-        drop_bank_sender: Sender<Vec<Arc<Bank>>>,
     ) -> Self {
         let ReplayStageConfig {
             my_pubkey,
@@ -611,7 +610,6 @@ impl ReplayStage {
                             &mut has_new_vote_been_rooted,
                             &mut replay_timing,
                             &voting_sender,
-                            &drop_bank_sender,
                         );
                     };
                     voting_time.stop();
@@ -1336,7 +1334,6 @@ impl ReplayStage {
         has_new_vote_been_rooted: &mut bool,
         replay_timing: &mut ReplayTiming,
         voting_sender: &Sender<VoteOp>,
-        bank_drop_sender: &Sender<Vec<Arc<Bank>>>,
     ) {
         if bank.is_empty() {
             inc_new_counter_info!("replay_stage-voted_empty_bank", 1);
@@ -1386,7 +1383,6 @@ impl ReplayStage {
                 unfrozen_gossip_verified_vote_hashes,
                 has_new_vote_been_rooted,
                 vote_signatures,
-                bank_drop_sender,
             );
             rpc_subscriptions.notify_roots(rooted_slots);
             if let Some(sender) = bank_notification_sender {
@@ -2409,19 +2405,21 @@ impl ReplayStage {
         unfrozen_gossip_verified_vote_hashes: &mut UnfrozenGossipVerifiedVoteHashes,
         has_new_vote_been_rooted: &mut bool,
         voted_signatures: &mut Vec<Signature>,
-        bank_drop_sender: &Sender<Vec<Arc<Bank>>>,
     ) {
         let removed_banks = bank_forks.write().unwrap().set_root(
             new_root,
             accounts_background_request_sender,
             highest_confirmed_root,
         );
-        bank_drop_sender
+        let mut dropped_banks_time = Measure::start("handle_new_root::drop_banks");
-            .send(removed_banks)
+        drop(removed_banks);
-            .unwrap_or_else(|err| warn!("bank drop failed: {:?}", err));
+        dropped_banks_time.stop();
-
+        if dropped_banks_time.as_ms() > 10 {
-        // Dropping the bank_forks write lock and reacquiring as a read lock is
+            datapoint_info!(
-        // safe because updates to bank_forks are only made by a single thread.
+                "handle_new_root-dropped_banks",
+                ("elapsed_ms", dropped_banks_time.as_ms(), i64)
+            );
+        }
         let r_bank_forks = bank_forks.read().unwrap();
         let new_root_bank = &r_bank_forks[new_root];
         if !*has_new_vote_been_rooted {
@@ -2878,7 +2876,6 @@ mod tests {
                     .map(|s| (s, HashMap::new()))
                     .collect(),
             };
-        let (bank_drop_sender, _bank_drop_receiver) = channel();
         ReplayStage::handle_new_root(
             root,
             &bank_forks,
@@ -2891,7 +2888,6 @@ mod tests {
             &mut unfrozen_gossip_verified_vote_hashes,
             &mut true,
             &mut Vec::new(),
-            &bank_drop_sender,
         );
         assert_eq!(bank_forks.read().unwrap().root(), root);
         assert_eq!(progress.len(), 1);
@@ -2951,7 +2947,6 @@ mod tests {
         for i in 0..=root {
             progress.insert(i, ForkProgress::new(Hash::default(), None, None, 0, 0));
         }
-        let (bank_drop_sender, _bank_drop_receiver) = channel();
         ReplayStage::handle_new_root(
             root,
             &bank_forks,
@@ -2964,7 +2959,6 @@ mod tests {
             &mut UnfrozenGossipVerifiedVoteHashes::default(),
             &mut true,
             &mut Vec::new(),
-            &bank_drop_sender,
         );
         assert_eq!(bank_forks.read().unwrap().root(), root);
         assert!(bank_forks.read().unwrap().get(confirmed_root).is_some());

core/src/tvu.rs

@@ -13,7 +13,6 @@ use crate::{
     completed_data_sets_service::CompletedDataSetsSender,
     consensus::Tower,
     cost_update_service::CostUpdateService,
-    drop_bank_service::DropBankService,
     ledger_cleanup_service::LedgerCleanupService,
     replay_stage::{ReplayStage, ReplayStageConfig},
     retransmit_stage::RetransmitStage,
@@ -71,7 +70,6 @@ pub struct Tvu {
     accounts_hash_verifier: AccountsHashVerifier,
     voting_service: VotingService,
     cost_update_service: CostUpdateService,
-    drop_bank_service: DropBankService,
 }
 
 pub struct Sockets {
@@ -299,9 +297,6 @@ impl Tvu {
             cost_update_receiver,
         );
 
-        let (drop_bank_sender, drop_bank_receiver) = channel();
-        let drop_bank_service = DropBankService::new(drop_bank_receiver);
-
         let replay_stage = ReplayStage::new(
             replay_stage_config,
             blockstore.clone(),
@@ -321,7 +316,6 @@ impl Tvu {
             cluster_slots_update_sender,
             voting_sender,
             cost_update_sender,
-            drop_bank_sender,
         );
 
         let ledger_cleanup_service = tvu_config.max_ledger_shreds.map(|max_ledger_shreds| {
@@ -354,7 +348,6 @@ impl Tvu {
             accounts_hash_verifier,
             voting_service,
             cost_update_service,
-            drop_bank_service,
         }
     }
 
@@ -370,7 +363,6 @@ impl Tvu {
         self.accounts_hash_verifier.join()?;
         self.voting_service.join()?;
         self.cost_update_service.join()?;
-        self.drop_bank_service.join()?;
         Ok(())
     }
 }