Cache account stores, flush from AccountsBackgroundService (#13140)

ledger/src/bank_forks_utils.rs

@@ -69,6 +69,7 @@ pub fn load(
                     process_options.debug_keys.clone(),
                     Some(&crate::builtins::get(process_options.bpf_jit)),
                     process_options.account_indexes.clone(),
+                    process_options.accounts_db_caching_enabled,
                 )
                 .expect("Load from snapshot failed");
                 if let Some(shrink_paths) = shrink_paths {

ledger/src/blockstore_processor.rs

@@ -346,6 +346,7 @@ pub struct ProcessOptions {
     pub frozen_accounts: Vec<Pubkey>,
     pub debug_keys: Option<Arc<HashSet<Pubkey>>>,
     pub account_indexes: HashSet<AccountIndex>,
+    pub accounts_db_caching_enabled: bool,
 }
 
 pub fn process_blockstore(
@@ -371,6 +372,7 @@ pub fn process_blockstore(
         opts.debug_keys.clone(),
         Some(&crate::builtins::get(opts.bpf_jit)),
         opts.account_indexes.clone(),
+        opts.accounts_db_caching_enabled,
     );
     let bank0 = Arc::new(bank0);
     info!("processing ledger for slot 0...");
@@ -929,6 +931,8 @@ fn load_frozen_forks(
                 new_root_bank.squash();
 
                 if last_free.elapsed() > Duration::from_secs(10) {
+                    // Must be called after `squash()`, so that AccountsDb knows what
+                    // the roots are for the cache flushing in exhaustively_free_unused_resource().
                     // This could take few secs; so update last_free later
                     new_root_bank.exhaustively_free_unused_resource();
                     last_free = Instant::now();
@@ -2901,6 +2905,7 @@ pub mod tests {
             None,
             None,
             HashSet::new(),
+            false,
         );
         *bank.epoch_schedule()
     }