Stake cache size (#26071)

* reduce threadpool for stake processing

* wip

* Revert "reduce threadpool for stake processing"

This reverts commit 004a4f872ea7a3ef53e38d145b6350c3f57c680c.

* batch update stake_cache

* fix deadlock

* add test

* code review feedbacks

* more review feedbacks

* fix conflicts

* report stake account len and vote account len at epoch boundary

* report num_staked_nodes

* remove batch store, no atomic for redeem timing

runtime/src/bank.rs

@@ -2710,6 +2710,10 @@ impl Bank {
             validator_rewards_paid, validator_rewards
         );
 
+        let num_stake_accounts = self.stakes_cache.num_stake_accounts();
+        let num_vote_accounts = self.stakes_cache.num_vote_accounts();
+        let num_staked_nodes = self.stakes_cache.num_staked_nodes();
+
         self.capitalization
             .fetch_add(validator_rewards_paid, Relaxed);
 
@@ -2731,7 +2735,10 @@ impl Bank {
             ("validator_rewards", validator_rewards_paid, i64),
             ("active_stake", active_stake, i64),
             ("pre_capitalization", capitalization, i64),
-            ("post_capitalization", self.capitalization(), i64)
+            ("post_capitalization", self.capitalization(), i64),
+            ("num_stake_accounts", num_stake_accounts as i64, i64),
+            ("num_vote_accounts", num_vote_accounts as i64, i64),
+            ("num_staked_nodes", num_staked_nodes as i64, i64)
         );
     }
 

runtime/src/stakes.rs

@@ -57,6 +57,21 @@ impl StakesCache {
         self.0.read().unwrap()
     }
 
+    pub fn num_stake_accounts(&self) -> usize {
+        let stakes = self.0.read().unwrap();
+        stakes.stake_delegations.len()
+    }
+
+    pub fn num_vote_accounts(&self) -> usize {
+        let stakes = self.0.read().unwrap();
+        stakes.vote_accounts.num_vote_accounts()
+    }
+
+    pub fn num_staked_nodes(&self) -> usize {
+        let stakes = self.0.read().unwrap();
+        stakes.vote_accounts.num_staked_nodes()
+    }
+
     pub fn check_and_store(&self, pubkey: &Pubkey, account: &AccountSharedData) {
         // TODO: If the account is already cached as a vote or stake account
         // but the owner changes, then this needs to evict the account from

runtime/src/vote_account.rs

@@ -60,6 +60,16 @@ pub struct VoteAccounts {
     staked_nodes_once: Once,
 }
 
+impl VoteAccounts {
+    pub fn num_vote_accounts(&self) -> usize {
+        self.vote_accounts.len()
+    }
+
+    pub fn num_staked_nodes(&self) -> usize {
+        self.staked_nodes.read().unwrap().len()
+    }
+}
+
 impl VoteAccount {
     pub(crate) fn lamports(&self) -> u64 {
         self.0.account.lamports()