add unref_zero_count stat

anza-xyz · Aug 29, 2024 · 7cfae31 · 7cfae31
1 parent 39af57f
commit 7cfae31
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Showing 3 changed files with 17 additions and 0 deletions.
diff --git a/accounts-db/src/accounts_db.rs b/accounts-db/src/accounts_db.rs
@@ -2035,6 +2035,7 @@ pub struct ShrinkStats {
     accounts_loaded: AtomicU64,
     purged_zero_lamports: AtomicU64,
     accounts_not_found_in_index: AtomicU64,
+    pub(crate) unref_zero_count: AtomicU64,
 }
 
 impl ShrinkStats {
@@ -2143,6 +2144,11 @@ impl ShrinkStats {
                     self.accounts_not_found_in_index.swap(0, Ordering::Relaxed),
                     i64
                 ),
+                (
+                    "unref_zero_count",
+                    self.unref_zero_count.swap(0, Ordering::Relaxed),
+                    i64
+                ),
             );
         }
     }
@@ -3315,6 +3321,7 @@ impl AccountsDb {
                     .iter_mut()
                     .for_each(|(candidate_pubkey, candidate_info)| {
                         self.accounts_index.scan(
+                            &self.shrink_stats,
                             [*candidate_pubkey].iter(),
                             |_candidate_pubkey, slot_list_and_ref_count, _entry| {
                                 let mut useless = true;
@@ -3919,6 +3926,7 @@ impl AccountsDb {
         let mut index_entries_being_shrunk = Vec::with_capacity(accounts.len());
         let latest_full_snapshot_slot = self.latest_full_snapshot_slot();
         self.accounts_index.scan(
+            &self.shrink_stats,
             accounts.iter().map(|account| account.pubkey()),
             |pubkey, slots_refs, entry| {
                 let mut result = AccountsIndexScanResult::OnlyKeepInMemoryIfDirty;
@@ -4188,6 +4196,7 @@ impl AccountsDb {
         // we have to unref before we `purge_keys_exact`. Otherwise, we could race with the foreground with tx processing
         // reviving this index entry and then we'd unref the revived version, which is a refcount bug.
         self.accounts_index.scan(
+            &self.shrink_stats,
             zero_lamport_single_ref_pubkeys.iter().cloned(),
             |_pubkey, _slots_refs, _entry| AccountsIndexScanResult::Unref,
             Some(AccountsIndexScanResult::Unref),
@@ -4296,6 +4305,7 @@ impl AccountsDb {
                 .fetch_add(1, Ordering::Relaxed);
 
             self.accounts_index.scan(
+            &self.shrink_stats,
                 shrink_collect.unrefed_pubkeys.into_iter(),
                 |pubkey, _slot_refs, entry| {
                     // pubkeys in `unrefed_pubkeys` were unref'd in `shrink_collect` above under the assumption that we would shrink everything.
@@ -8144,6 +8154,7 @@ impl AccountsDb {
             (0..batches).into_par_iter().for_each(|batch| {
                 let skip = batch * UNREF_ACCOUNTS_BATCH_SIZE;
                 self.accounts_index.scan(
+                    &self.shrink_stats,
                     pubkeys
                         .clone()
                         .skip(skip)
@@ -9216,6 +9227,7 @@ impl AccountsDb {
         let mut removed_rent_paying = 0;
         let mut removed_top_off = 0;
         self.accounts_index.scan(
+            &self.shrink_stats,
             pubkeys.iter(),
             |pubkey, slots_refs, _entry| {
                 if let Some((slot_list, _ref_count)) = slots_refs {

diff --git a/accounts-db/src/accounts_index.rs b/accounts-db/src/accounts_index.rs
@@ -1,6 +1,7 @@
 pub(crate) mod in_mem_accounts_index;
 use {
     crate::{
+        accounts_db::ShrinkStats,
         accounts_index_storage::{AccountsIndexStorage, Startup},
         accounts_partition::RentPayingAccountsByPartition,
         ancestors::Ancestors,
@@ -1395,6 +1396,7 @@ impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
     ///     None.
     pub(crate) fn scan<'a, F, I>(
         &self,
+        stat: &ShrinkStats,
         pubkeys: I,
         mut callback: F,
         avoid_callback_result: Option<AccountsIndexScanResult>,
@@ -1437,6 +1439,7 @@ impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
                             AccountsIndexScanResult::Unref => {
                                 if locked_entry.unref() {
                                     info!("scan: refcount of item already at 0: {pubkey}");
+                                    stat.unref_zero_count.fetch_add(1, Ordering::Relaxed);
                                 }
                                 true
                             }

diff --git a/accounts-db/src/ancient_append_vecs.rs b/accounts-db/src/ancient_append_vecs.rs
@@ -491,6 +491,7 @@ impl AccountsDb {
         self.thread_pool_clean.install(|| {
             accounts_to_combine.into_par_iter().for_each(|combine| {
                 self.accounts_index.scan(
+                    &self.shrink_stats,
                     combine.unrefed_pubkeys.into_iter(),
                     |_pubkey, _slots_refs, entry| {
                         if let Some(entry) = entry {
@@ -3886,6 +3887,7 @@ pub mod tests {
             };
             db.addref_accounts_failed_to_shrink_ancient(accounts_to_combine.accounts_to_combine);
             db.accounts_index.scan(
+                &db.shrink_stats,
                 unrefed_pubkeys.iter(),
                 |k, slot_refs, _entry| {
                     assert_eq!(expected_ref_counts.remove(k).unwrap(), slot_refs.unwrap().1);