Minimally intrusive conservative cache tuning (#1269)

* Minimally intrusive conservative cache tuning * Update txdb.h * Update dbwrapper.cpp * Tune to use powers of 2 * Update dbwrapper.cpp * Add casts * Update dbwrapper.cpp * Update dbwrapper.cpp
DeFiCh · May 24, 2022 · 120282a · 120282a
1 parent 95908f6
commit 120282a
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/src/dbwrapper.cpp b/src/dbwrapper.cpp
@@ -99,10 +99,18 @@ static void SetMaxOpenFiles(leveldb::Options *options) {
 
 static leveldb::Options GetOptions(size_t nCacheSize)
 {
+    const auto ceil_power_of_two = [](size_t v) {
+        v--;
+        for (const size_t i: {1, 2, 4, 6, 16}) v |= v >> i;
+        v++;
+        return v;
+    };
+
     leveldb::Options options;
     options.block_cache = leveldb::NewLRUCache(nCacheSize / 2);
-    options.write_buffer_size = nCacheSize / 4; // up to two write buffers may be held in memory simultaneously
-    options.filter_policy = leveldb::NewBloomFilterPolicy(10);
+    options.write_buffer_size = ceil_power_of_two(std::min(static_cast<size_t>(64)
+     << 20, nCacheSize / 4)); // Max of 64mb -more is not useful
+    options.filter_policy = leveldb::NewBloomFilterPolicy(16);
     options.compression = leveldb::kNoCompression;
     options.info_log = new CDefiLevelDBLogger();
     if (leveldb::kMajorVersion > 1 || (leveldb::kMajorVersion == 1 && leveldb::kMinorVersion >= 16)) {

diff --git a/src/txdb.h b/src/txdb.h
@@ -24,15 +24,15 @@ class uint256;
 //! No need to periodic flush if at least this much space still available.
 static constexpr int MAX_BLOCK_COINSDB_USAGE = 10;
 //! -dbcache default (MiB)
-static const int64_t nDefaultDbCache = 450;
+static const int64_t nDefaultDbCache = 512;
 //! -dbbatchsize default (bytes)
 static const int64_t nDefaultDbBatchSize = 16 << 20;
 //! max. -dbcache (MiB)
 static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
 //! min. -dbcache (MiB)
 static const int64_t nMinDbCache = 4;
 //! Max memory allocated to block tree DB specific cache, if no -txindex (MiB)
-static const int64_t nMaxBlockDBCache = 2;
+static const int64_t nMaxBlockDBCache = 4;
 //! Max memory allocated to block tree DB specific cache, if -txindex (MiB)
 // Unlike for the UTXO database, for the txindex scenario the leveldb cache make
 // a meaningful difference: https://github.com/bitcoin/bitcoin/pull/8273#issuecomment-229601991