From 88d8d9fad0c3fb0a5102c6a01c16798ea2ac3b33 Mon Sep 17 00:00:00 2001 From: Arkadiy Paronyan Date: Wed, 14 Jul 2021 13:29:03 +0200 Subject: [PATCH] Improve shared state cache contention (#9321) --- client/db/src/lib.rs | 4 +- client/db/src/storage_cache.rs | 69 +++++++++++++++++++--------------- 2 files changed, 41 insertions(+), 32 deletions(-) diff --git a/client/db/src/lib.rs b/client/db/src/lib.rs index 94535cf28aea5..527fcb99645e1 100644 --- a/client/db/src/lib.rs +++ b/client/db/src/lib.rs @@ -1466,7 +1466,7 @@ impl Backend { self.changes_tries_storage.post_commit(changes_trie_cache_ops); if let Some((enacted, retracted)) = cache_update { - self.shared_cache.lock().sync(&enacted, &retracted); + self.shared_cache.write().sync(&enacted, &retracted); } for (hash, number, is_best, is_finalized) in meta_updates { @@ -1849,7 +1849,7 @@ impl sc_client_api::backend::Backend for Backend { ); let database_cache = MemorySize::from_bytes(0); let state_cache = MemorySize::from_bytes( - (*&self.shared_cache).lock().used_storage_cache_size(), + (*&self.shared_cache).read().used_storage_cache_size(), ); let state_db = self.storage.state_db.memory_info(); diff --git a/client/db/src/storage_cache.rs b/client/db/src/storage_cache.rs index 8929972e26e66..c7ea5f45c4bd8 100644 --- a/client/db/src/storage_cache.rs +++ b/client/db/src/storage_cache.rs @@ -23,7 +23,7 @@ use std::collections::{VecDeque, HashSet, HashMap}; use std::sync::Arc; use std::hash::Hash as StdHash; -use parking_lot::{Mutex, RwLock, RwLockUpgradableReadGuard}; +use parking_lot::{RwLock, RwLockUpgradableReadGuard}; use linked_hash_map::{LinkedHashMap, Entry}; use hash_db::Hasher; use sp_runtime::traits::{Block as BlockT, Header, HashFor, NumberFor}; @@ -222,7 +222,7 @@ impl Cache { } } -pub type SharedCache = Arc>>; +pub type SharedCache = Arc>>; /// Fix lru storage size for hash (small 64ko). const FIX_LRU_HASH_SIZE: usize = 65_536; @@ -234,7 +234,7 @@ pub fn new_shared_cache( ) -> SharedCache { let top = child_ratio.1.saturating_sub(child_ratio.0); Arc::new( - Mutex::new( + RwLock::new( Cache { lru_storage: LRUMap( LinkedHashMap::new(), 0, shared_cache_size * top / child_ratio.1 @@ -337,7 +337,7 @@ impl CacheChanges { commit_number: Option>, is_best: bool, ) { - let mut cache = self.shared_cache.lock(); + let mut cache = self.shared_cache.write(); trace!( "Syncing cache, id = (#{:?}, {:?}), parent={:?}, best={}", commit_number, @@ -527,12 +527,15 @@ impl>, B: BlockT> StateBackend> for Cachin return Ok(entry) } - let mut cache = self.cache.shared_cache.lock(); - if Self::is_allowed(Some(key), None, &self.cache.parent_hash, &cache.modifications) { - if let Some(entry) = cache.lru_storage.get(key).map(|a| a.clone()) { - trace!("Found in shared cache: {:?}", HexDisplay::from(&key)); - self.usage.tally_key_read(key, entry.as_ref(), true); - return Ok(entry) + { + let cache = self.cache.shared_cache.upgradable_read(); + if Self::is_allowed(Some(key), None, &self.cache.parent_hash, &cache.modifications) { + let mut cache = RwLockUpgradableReadGuard::upgrade(cache); + if let Some(entry) = cache.lru_storage.get(key).map(|a| a.clone()) { + trace!("Found in shared cache: {:?}", HexDisplay::from(&key)); + self.usage.tally_key_read(key, entry.as_ref(), true); + return Ok(entry) + } } } trace!("Cache miss: {:?}", HexDisplay::from(&key)); @@ -548,11 +551,14 @@ impl>, B: BlockT> StateBackend> for Cachin trace!("Found hash in local cache: {:?}", HexDisplay::from(&key)); return Ok(entry) } - let mut cache = self.cache.shared_cache.lock(); - if Self::is_allowed(Some(key), None, &self.cache.parent_hash, &cache.modifications) { - if let Some(entry) = cache.lru_hashes.get(key).map(|a| a.0.clone()) { - trace!("Found hash in shared cache: {:?}", HexDisplay::from(&key)); - return Ok(entry) + { + let cache = self.cache.shared_cache.upgradable_read(); + if Self::is_allowed(Some(key), None, &self.cache.parent_hash, &cache.modifications) { + let mut cache = RwLockUpgradableReadGuard::upgrade(cache); + if let Some(entry) = cache.lru_hashes.get(key).map(|a| a.0.clone()) { + trace!("Found hash in shared cache: {:?}", HexDisplay::from(&key)); + return Ok(entry) + } } } trace!("Cache hash miss: {:?}", HexDisplay::from(&key)); @@ -574,13 +580,16 @@ impl>, B: BlockT> StateBackend> for Cachin self.usage.tally_child_key_read(&key, entry, true) ) } - let mut cache = self.cache.shared_cache.lock(); - if Self::is_allowed(None, Some(&key), &self.cache.parent_hash, &cache.modifications) { - if let Some(entry) = cache.lru_child_storage.get(&key).map(|a| a.clone()) { - trace!("Found in shared cache: {:?}", key); - return Ok( - self.usage.tally_child_key_read(&key, entry, true) - ) + { + let cache = self.cache.shared_cache.upgradable_read(); + if Self::is_allowed(None, Some(&key), &self.cache.parent_hash, &cache.modifications) { + let mut cache = RwLockUpgradableReadGuard::upgrade(cache); + if let Some(entry) = cache.lru_child_storage.get(&key).map(|a| a.clone()) { + trace!("Found in shared cache: {:?}", key); + return Ok( + self.usage.tally_child_key_read(&key, entry, true) + ) + } } } trace!("Cache miss: {:?}", key); @@ -1250,7 +1259,7 @@ mod tests { true, ); // 32 key, 3 byte size - assert_eq!(shared.lock().used_storage_cache_size(), 35 /* bytes */); + assert_eq!(shared.read().used_storage_cache_size(), 35 /* bytes */); let key = H256::random()[..].to_vec(); s.cache.sync_cache( @@ -1263,7 +1272,7 @@ mod tests { true, ); // 35 + (2 * 32) key, 2 byte size - assert_eq!(shared.lock().used_storage_cache_size(), 101 /* bytes */); + assert_eq!(shared.read().used_storage_cache_size(), 101 /* bytes */); } #[test] @@ -1289,7 +1298,7 @@ mod tests { true, ); // 32 key, 4 byte size - assert_eq!(shared.lock().used_storage_cache_size(), 36 /* bytes */); + assert_eq!(shared.read().used_storage_cache_size(), 36 /* bytes */); let key = H256::random()[..].to_vec(); s.cache.sync_cache( @@ -1302,7 +1311,7 @@ mod tests { true, ); // 32 key, 2 byte size - assert_eq!(shared.lock().used_storage_cache_size(), 34 /* bytes */); + assert_eq!(shared.read().used_storage_cache_size(), 34 /* bytes */); } #[test] @@ -1355,7 +1364,7 @@ mod tests { // Restart (or unknown block?), clear caches. { - let mut cache = s.cache.shared_cache.lock(); + let mut cache = s.cache.shared_cache.write(); let cache = &mut *cache; cache.lru_storage.clear(); cache.lru_hashes.clear(); @@ -1402,7 +1411,7 @@ mod tests { Some(1), true, ); - assert_eq!(shared.lock().lru_storage.get(&key).unwrap(), &Some(vec![1])); + assert_eq!(shared.write().lru_storage.get(&key).unwrap(), &Some(vec![1])); let mut s = CachingState::new( InMemoryBackend::::default(), @@ -1421,7 +1430,7 @@ mod tests { false, ); - assert_eq!(shared.lock().lru_storage.get(&key).unwrap(), &Some(vec![1])); + assert_eq!(shared.write().lru_storage.get(&key).unwrap(), &Some(vec![1])); let mut s = CachingState::new( InMemoryBackend::::default(), @@ -1776,7 +1785,7 @@ mod qc { std::mem::swap(fork_chain, &mut new_fork); - self.shared.lock().sync(&retracted, &enacted); + self.shared.write().sync(&retracted, &enacted); self.head_state( self.canon.last()