From 5a48ef72fd0c73b6f8082758010b18ba328b6eb5 Mon Sep 17 00:00:00 2001
From: Yueh-Hsuan Chiang <93241502+yhchiang-sol@users.noreply.github.com>
Date: Mon, 11 Apr 2022 20:39:46 -0700
Subject: [PATCH] (LedgerStore) Skip sampling check when
 ROCKSDB_PERF_CONTEXT_SAMPLES_IN_1K_DEFAULT = 0 (#24221)

#### Problem
Currently, even if SOLANA_METRICS_ROCKSDB_PERF_SAMPLES_IN_1K == 0, we are still doing
the sampling check for every RocksDB read.

```
thread_rng().gen_range(0, METRIC_SAMPLES_1K) > *ROCKSDB_PERF_CONTEXT_SAMPLES_IN_1K
```

#### Summary of Changes
This PR skips the sampling check when SOLANA_METRICS_ROCKSDB_PERF_SAMPLES_IN_1K
is set to 0.
---
 ledger/src/blockstore_db.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ledger/src/blockstore_db.rs b/ledger/src/blockstore_db.rs
index aa29de561d..5a7b7ef18c 100644
--- a/ledger/src/blockstore_db.rs
+++ b/ledger/src/blockstore_db.rs
@@ -2295,6 +2295,9 @@ mod rocks_metrics_utils {
     ///
     /// Returns true if the PerfContext is enabled.
     pub fn maybe_collect_perf_context() -> bool {
+        if *ROCKSDB_PERF_CONTEXT_SAMPLES_IN_1K <= 0 {
+            return false;
+        }
         if thread_rng().gen_range(0, METRIC_SAMPLES_1K) > *ROCKSDB_PERF_CONTEXT_SAMPLES_IN_1K {
             return false;
         }