diff --git a/accounts-db/src/accounts_db.rs b/accounts-db/src/accounts_db.rs index dda8614993aca7..342f7a30fb6c6b 100644 --- a/accounts-db/src/accounts_db.rs +++ b/accounts-db/src/accounts_db.rs @@ -2438,7 +2438,10 @@ impl AccountsDb { base_working_path: Option, ) -> Self { let num_threads = get_thread_count(); - const MAX_READ_ONLY_CACHE_DATA_SIZE: usize = 400_000_000; // 400M bytes + // 400M bytes + const MAX_READ_ONLY_CACHE_DATA_SIZE: usize = 400_000_000; + // read only cache does not update lru on read of an entry unless it has been at least this many ms since the last lru update + const READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE: u32 = 100; let (base_working_path, accounts_hash_cache_path, temp_accounts_hash_cache_path) = match base_working_path { @@ -2483,7 +2486,10 @@ impl AccountsDb { storage: AccountStorage::default(), accounts_cache: AccountsCache::default(), sender_bg_hasher: None, - read_only_accounts_cache: ReadOnlyAccountsCache::new(MAX_READ_ONLY_CACHE_DATA_SIZE), + read_only_accounts_cache: ReadOnlyAccountsCache::new( + MAX_READ_ONLY_CACHE_DATA_SIZE, + READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE, + ), recycle_stores: RwLock::new(RecycleStores::default()), uncleaned_pubkeys: DashMap::new(), next_id: AtomicAppendVecId::new(0), diff --git a/accounts-db/src/read_only_accounts_cache.rs b/accounts-db/src/read_only_accounts_cache.rs index d7a9d2bb4a0d42..27e0d848543c82 100644 --- a/accounts-db/src/read_only_accounts_cache.rs +++ b/accounts-db/src/read_only_accounts_cache.rs @@ -8,6 +8,7 @@ use { account::{AccountSharedData, ReadableAccount}, clock::Slot, pubkey::Pubkey, + timing::timestamp, }, std::sync::{ atomic::{AtomicU32, AtomicU64, AtomicUsize, Ordering}, @@ -23,7 +24,10 @@ type ReadOnlyCacheKey = (Pubkey, Slot); #[derive(Debug)] struct ReadOnlyAccountCacheEntry { account: AccountSharedData, - index: AtomicU32, // Index of the entry in the eviction queue. + /// Index of the entry in the eviction queue. + index: AtomicU32, + /// lower bits of last timestamp when eviction queue was updated, in ms + last_update_time: AtomicU32, } #[derive(Default, Debug)] @@ -53,7 +57,7 @@ impl ReadOnlyCacheStats { } #[derive(Debug)] -pub struct ReadOnlyAccountsCache { +pub(crate) struct ReadOnlyAccountsCache { cache: DashMap, /// When an item is first entered into the cache, it is added to the end of /// the queue. Also each time an entry is looked up from the cache it is @@ -63,18 +67,21 @@ pub struct ReadOnlyAccountsCache { queue: Mutex>, max_data_size: usize, data_size: AtomicUsize, + // read only cache does not update lru on read of an entry unless it has been at least this many ms since the last lru update + ms_to_skip_lru_update: u32, // Performance statistics stats: ReadOnlyCacheStats, } impl ReadOnlyAccountsCache { - pub(crate) fn new(max_data_size: usize) -> Self { + pub(crate) fn new(max_data_size: usize, ms_to_skip_lru_update: u32) -> Self { Self { max_data_size, cache: DashMap::default(), queue: Mutex::>::default(), data_size: AtomicUsize::default(), + ms_to_skip_lru_update, stats: ReadOnlyCacheStats::default(), } } @@ -103,10 +110,15 @@ impl ReadOnlyAccountsCache { // Move the entry to the end of the queue. // self.queue is modified while holding a reference to the cache entry; // so that another thread cannot write to the same key. - { + // If we updated the eviction queue within this much time, then leave it where it is. We're likely to hit it again. + let update_lru = entry.ms_since_last_update() >= self.ms_to_skip_lru_update; + if update_lru { let mut queue = self.queue.lock().unwrap(); queue.remove(entry.index()); entry.set_index(queue.insert_last(key)); + entry + .last_update_time + .store(ReadOnlyAccountCacheEntry::timestamp(), Ordering::Release); } let account = entry.account.clone(); drop(entry); @@ -185,7 +197,11 @@ impl ReadOnlyAccountCacheEntry { fn new(account: AccountSharedData, index: Index) -> Self { let index = unsafe { std::mem::transmute::(index) }; let index = AtomicU32::new(index); - Self { account, index } + Self { + account, + index, + last_update_time: AtomicU32::new(Self::timestamp()), + } } #[inline] @@ -199,6 +215,16 @@ impl ReadOnlyAccountCacheEntry { let index = unsafe { std::mem::transmute::(index) }; self.index.store(index, Ordering::Relaxed); } + + /// lower bits of current timestamp. We don't need higher bits and u32 packs with Index u32 in `ReadOnlyAccountCacheEntry` + fn timestamp() -> u32 { + timestamp() as u32 + } + + /// ms since `last_update_time` timestamp + fn ms_since_last_update(&self) -> u32 { + Self::timestamp().wrapping_sub(self.last_update_time.load(Ordering::Acquire)) + } } #[cfg(test)] @@ -226,7 +252,8 @@ mod tests { let per_account_size = CACHE_ENTRY_SIZE; let data_size = 100; let max = data_size + per_account_size; - let cache = ReadOnlyAccountsCache::new(max); + let cache = + ReadOnlyAccountsCache::new(max, READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE_FOR_TESTS); let slot = 0; assert!(cache.load(Pubkey::default(), slot).is_none()); assert_eq!(0, cache.cache_len()); @@ -261,7 +288,8 @@ mod tests { // can store 2 items, 3rd item kicks oldest item out let max = (data_size + per_account_size) * 2; - let cache = ReadOnlyAccountsCache::new(max); + let cache = + ReadOnlyAccountsCache::new(max, READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE_FOR_TESTS); cache.store(key1, slot, account1.clone()); assert_eq!(100 + per_account_size, cache.data_size()); assert!(accounts_equal(&cache.load(key1, slot).unwrap(), &account1)); @@ -284,13 +312,19 @@ mod tests { assert_eq!(2, cache.cache_len()); } + /// tests like to deterministically update lru always + const READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE_FOR_TESTS: u32 = 0; + #[test] fn test_read_only_accounts_cache_random() { const SEED: [u8; 32] = [0xdb; 32]; const DATA_SIZE: usize = 19; const MAX_CACHE_SIZE: usize = 17 * (CACHE_ENTRY_SIZE + DATA_SIZE); let mut rng = ChaChaRng::from_seed(SEED); - let cache = ReadOnlyAccountsCache::new(MAX_CACHE_SIZE); + let cache = ReadOnlyAccountsCache::new( + MAX_CACHE_SIZE, + READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE_FOR_TESTS, + ); let slots: Vec = repeat_with(|| rng.gen_range(0..1000)).take(5).collect(); let pubkeys: Vec = repeat_with(|| { let mut arr = [0u8; 32];