shink all in parallel on startup (#17308)

runtime/src/accounts_db.rs

@@ -2171,7 +2171,16 @@ impl AccountsDb {
         num_candidates
     }
 
-    pub fn shrink_all_slots(&self) {
+    pub fn shrink_all_slots(&self, is_startup: bool) {
+        if is_startup && self.caching_enabled {
+            let slots = self.all_slots_in_storage();
+            let chunk_size = std::cmp::max(slots.len() / 8, 1); // approximately 400k slots in a snapshot
+            slots.par_chunks(chunk_size).for_each(|slots| {
+                for slot in slots {
+                    self.shrink_slot_forced(*slot);
+                }
+            });
+        } else {
             for slot in self.all_slots_in_storage() {
                 if self.caching_enabled {
                     self.shrink_slot_forced(slot);
@@ -2180,6 +2189,7 @@ impl AccountsDb {
                 }
             }
         }
+    }
 
     pub fn scan_accounts<F, A>(&self, ancestors: &Ancestors, scan_func: F) -> A
     where
@@ -8445,13 +8455,15 @@ pub mod tests {
 
     #[test]
     fn test_shrink_all_slots_none() {
+        for startup in &[false, true] {
             let accounts = AccountsDb::new_single();
 
             for _ in 0..10 {
                 accounts.shrink_candidate_slots();
             }
 
-        accounts.shrink_all_slots();
+            accounts.shrink_all_slots(*startup);
+        }
     }
 
     #[test]
@@ -8532,6 +8544,7 @@ pub mod tests {
     fn test_shrink_stale_slots_processed() {
         solana_logger::setup();
 
+        for startup in &[false, true] {
             let accounts = AccountsDb::new_single();
 
             let pubkey_count = 100;
@@ -8571,7 +8584,7 @@ pub mod tests {
                 pubkey_count,
                 accounts.all_account_count_in_append_vec(shrink_slot)
             );
-        accounts.shrink_all_slots();
+            accounts.shrink_all_slots(*startup);
             assert_eq!(
                 pubkey_count_after_shrink,
                 accounts.all_account_count_in_append_vec(shrink_slot)
@@ -8589,12 +8602,13 @@ pub mod tests {
                 .unwrap();
 
             // repeating should be no-op
-        accounts.shrink_all_slots();
+            accounts.shrink_all_slots(*startup);
             assert_eq!(
                 pubkey_count_after_shrink,
                 accounts.all_account_count_in_append_vec(shrink_slot)
             );
         }
+    }
 
     #[test]
     fn test_shrink_candidate_slots() {
@@ -8648,7 +8662,7 @@ pub mod tests {
         );
 
         // Now, do full-shrink.
-        accounts.shrink_all_slots();
+        accounts.shrink_all_slots(false);
         assert_eq!(
             pubkey_count_after_shrink,
             accounts.all_account_count_in_append_vec(shrink_slot)
@@ -8708,7 +8722,7 @@ pub mod tests {
         );
 
         // Now, do full-shrink.
-        accounts.shrink_all_slots();
+        accounts.shrink_all_slots(false);
         assert_eq!(
             pubkey_count_after_shrink,
             accounts.all_account_count_in_append_vec(shrink_slot)
@@ -8910,7 +8924,7 @@ pub mod tests {
         }
         accounts.add_root(1);
         accounts.clean_accounts(None);
-        accounts.shrink_all_slots();
+        accounts.shrink_all_slots(false);
         accounts.print_accounts_stats("post-shrink");
         let num_stores = accounts.recycle_stores.read().unwrap().entry_count();
         assert!(num_stores > 0);

runtime/src/bank.rs

@@ -2122,7 +2122,7 @@ impl Bank {
         clean.stop();
 
         let mut shrink = Measure::start("shrink");
-        self.shrink_all_slots();
+        self.shrink_all_slots(false);
         shrink.stop();
 
         info!(
@@ -4527,7 +4527,7 @@ impl Bank {
 
         let mut shrink_all_slots_time = Measure::start("shrink_all_slots");
         if self.slot() > 0 {
-            self.shrink_all_slots();
+            self.shrink_all_slots(true);
         }
         shrink_all_slots_time.stop();
 
@@ -4816,8 +4816,8 @@ impl Bank {
         self.rc.accounts.accounts_db.clean_accounts(max_clean_slot);
     }
 
-    pub fn shrink_all_slots(&self) {
-        self.rc.accounts.accounts_db.shrink_all_slots();
+    pub fn shrink_all_slots(&self, is_startup: bool) {
+        self.rc.accounts.accounts_db.shrink_all_slots(is_startup);
     }
 
     pub fn print_accounts_stats(&self) {