From 89ba3ff1392e08c293275629de902e3f2c538d85 Mon Sep 17 00:00:00 2001
From: "Jeff Washington (jwash)" <wash678@gmail.com>
Date: Tue, 22 Mar 2022 09:19:38 -0500
Subject: [PATCH] log fail to evict (#23815)

---
 runtime/src/bucket_map_holder_stats.rs | 6 ++++++
 runtime/src/in_mem_accounts_index.rs   | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/runtime/src/bucket_map_holder_stats.rs b/runtime/src/bucket_map_holder_stats.rs
index 1a0cd118eb..713318ce94 100644
--- a/runtime/src/bucket_map_holder_stats.rs
+++ b/runtime/src/bucket_map_holder_stats.rs
@@ -29,6 +29,7 @@ pub struct BucketMapHolderStats {
     pub updates_in_mem: AtomicU64,
     pub items: AtomicU64,
     pub items_us: AtomicU64,
+    pub failed_to_evict: AtomicU64,
     pub keys: AtomicU64,
     pub deletes: AtomicU64,
     pub inserts: AtomicU64,
@@ -319,6 +320,11 @@ impl BucketMapHolderStats {
                     self.entry_missing_us.swap(0, Ordering::Relaxed),
                     i64
                 ),
+                (
+                    "failed_to_evict",
+                    self.failed_to_evict.swap(0, Ordering::Relaxed),
+                    i64
+                ),
                 (
                     "updates_in_mem",
                     self.updates_in_mem.swap(0, Ordering::Relaxed),
diff --git a/runtime/src/in_mem_accounts_index.rs b/runtime/src/in_mem_accounts_index.rs
index 121e29e7fb..72fe753c70 100644
--- a/runtime/src/in_mem_accounts_index.rs
+++ b/runtime/src/in_mem_accounts_index.rs
@@ -1104,6 +1104,8 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
             return;
         }
 
+        let mut failed = 0;
+
         // skip any keys that are held in memory because of ranges being held
         let ranges = self.cache_ranges_held.read().unwrap().clone();
         if !ranges.is_empty() {
@@ -1118,6 +1120,7 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
                 }
             });
             if !move_age.is_empty() {
+                failed += move_age.len();
                 self.move_ages_to_future(next_age_on_failure, current_age, &move_age);
             }
         }
@@ -1131,6 +1134,7 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
                     let v = occupied.get();
                     if Arc::strong_count(v) > 1 {
                         // someone is holding the value arc's ref count and could modify it, so do not evict
+                        failed += 1;
                         v.try_exchange_age(next_age_on_failure, current_age);
                         continue;
                     }
@@ -1142,11 +1146,13 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
                         // marked dirty or bumped in age after we looked above
                         // these evictions will be handled in later passes (at later ages)
                         // but, at startup, everything is ready to age out if it isn't dirty
+                        failed += 1;
                         continue;
                     }
 
                     if stop_evictions_changes_at_start != self.get_stop_evictions_changes() {
                         // ranges were changed
+                        failed += 1;
                         v.try_exchange_age(next_age_on_failure, current_age);
                         continue;
                     }
@@ -1163,6 +1169,7 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
         self.stats()
             .insert_or_delete_mem_count(false, self.bin, evicted);
         Self::update_stat(&self.stats().flush_entries_evicted_from_mem, evicted as u64);
+        Self::update_stat(&self.stats().failed_to_evict, failed as u64);
     }
 
     pub fn stats(&self) -> &BucketMapHolderStats {