From 1560d5e3c389191de175f438e72958895fb68b8e Mon Sep 17 00:00:00 2001
From: "Jeff Washington (jwash)"
 <75863576+jeffwashington@users.noreply.github.com>
Date: Tue, 7 Sep 2021 11:51:59 -0500
Subject: [PATCH] collect rent in parallel for partitions (#19478)

* collect rent in parallel for partitions

* combine use

* use fg accounts db thread pool
---
 runtime/src/bank.rs | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index cecddf24ea..0e040612da 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -65,7 +65,10 @@ use crate::{
 use byteorder::{ByteOrder, LittleEndian};
 use itertools::Itertools;
 use log::*;
-use rayon::ThreadPool;
+use rayon::{
+    iter::{IntoParallelIterator, ParallelIterator},
+    ThreadPool,
+};
 use solana_measure::measure::Measure;
 use solana_metrics::{datapoint_debug, inc_new_counter_debug, inc_new_counter_info};
 use solana_program_runtime::{ExecuteDetailsTimings, Executors};
@@ -3858,9 +3861,13 @@ impl Bank {
         }
 
         let mut measure = Measure::start("collect_rent_eagerly-ms");
-        for partition in self.rent_collection_partitions() {
-            self.collect_rent_in_partition(partition);
-        }
+        self.rc.accounts.accounts_db.thread_pool.install(|| {
+            self.rent_collection_partitions()
+                .into_par_iter()
+                .for_each(|partition| {
+                    self.collect_rent_in_partition(partition);
+                });
+        });
         measure.stop();
         inc_new_counter_info!("collect_rent_eagerly-ms", measure.as_ms() as usize);
     }