From cf1f323339fa4f0e0695497f5d84da9cd34a4e57 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 9 Sep 2025 12:40:04 +0900 Subject: [PATCH 1/2] Replace callers of dynahash.h's my_log() by equivalent in pg_bitutils.h All these callers use 4-byte signed integers for their variables, hence they do not require my_log2() maximum based on int64. This eases an upcoming removal of my_log2(). ExecChooseHashTableSize(), that calculates the number of buckets to use for hash tables, is now capped at 2^30, to keep pg_ceil_log2_32() on the same side. nodeAgg.c is already capped at 1024, and worker.c relies on the maximum number of subxacts. --- src/backend/executor/nodeAgg.c | 3 +-- src/backend/executor/nodeHash.c | 14 ++++++++++---- src/backend/replication/logical/worker.c | 3 +-- 3 files changed, 12 insertions(+), 8 deletions(-) diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index 377e016d7322..a4f3d30f307c 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -267,7 +267,6 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/datum.h" -#include "utils/dynahash.h" #include "utils/expandeddatum.h" #include "utils/injection_point.h" #include "utils/logtape.h" @@ -2115,7 +2114,7 @@ hash_choose_num_partitions(double input_groups, double hashentrysize, npartitions = (int) dpartitions; /* ceil(log2(npartitions)) */ - partition_bits = my_log2(npartitions); + partition_bits = pg_ceil_log2_32(npartitions); /* make sure that we don't exhaust the hash bits */ if (partition_bits + used_bits >= 32) diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c index 8d2201ab67fa..db8f4722ebb2 100644 --- a/src/backend/executor/nodeHash.c +++ b/src/backend/executor/nodeHash.c @@ -36,7 +36,6 @@ #include "executor/nodeHashjoin.h" #include "miscadmin.h" #include "port/pg_bitutils.h" -#include "utils/dynahash.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/syscache.h" @@ -340,7 +339,7 @@ MultiExecParallelHash(HashState *node) */ hashtable->curbatch = -1; hashtable->nbuckets = pstate->nbuckets; - hashtable->log2_nbuckets = my_log2(hashtable->nbuckets); + hashtable->log2_nbuckets = pg_ceil_log2_32(hashtable->nbuckets); hashtable->totalTuples = pstate->total_tuples; /* @@ -480,7 +479,7 @@ ExecHashTableCreate(HashState *state) &nbuckets, &nbatch, &num_skew_mcvs); /* nbuckets must be a power of 2 */ - log2_nbuckets = my_log2(nbuckets); + log2_nbuckets = pg_ceil_log2_32(nbuckets); Assert(nbuckets == (1 << log2_nbuckets)); /* @@ -935,6 +934,13 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, bool useskew, Assert(nbuckets > 0); Assert(nbatch > 0); + /* + * Cap nbuckets, for power of 2 calculations. This maximum is safe + * for pg_ceil_log2_32(). + */ + if (nbuckets > PG_INT32_MAX / 2) + nbuckets = PG_INT32_MAX / 2; + *numbuckets = nbuckets; *numbatches = nbatch; } @@ -3499,7 +3505,7 @@ ExecParallelHashTableSetCurrentBatch(HashJoinTable hashtable, int batchno) dsa_get_address(hashtable->area, hashtable->batches[batchno].shared->buckets); hashtable->nbuckets = hashtable->parallel_state->nbuckets; - hashtable->log2_nbuckets = my_log2(hashtable->nbuckets); + hashtable->log2_nbuckets = pg_ceil_log2_32(hashtable->nbuckets); hashtable->current_chunk = NULL; hashtable->current_chunk_shared = InvalidDsaPointer; hashtable->batches[batchno].at_least_one_chunk = false; diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c index f1ebd63e792e..274d1307d87f 100644 --- a/src/backend/replication/logical/worker.c +++ b/src/backend/replication/logical/worker.c @@ -276,7 +276,6 @@ #include "storage/procarray.h" #include "tcop/tcopprot.h" #include "utils/acl.h" -#include "utils/dynahash.h" #include "utils/guc.h" #include "utils/inval.h" #include "utils/lsyscache.h" @@ -5092,7 +5091,7 @@ subxact_info_read(Oid subid, TransactionId xid) len = sizeof(SubXactInfo) * subxact_data.nsubxacts; /* we keep the maximum as a power of 2 */ - subxact_data.nsubxacts_max = 1 << my_log2(subxact_data.nsubxacts); + subxact_data.nsubxacts_max = 1 << pg_ceil_log2_32(subxact_data.nsubxacts); /* * Allocate subxact information in the logical streaming context. We need From 3f2b3c881ed58ac407cd1b35dc240182e0b70357 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 9 Sep 2025 12:42:48 +0900 Subject: [PATCH 2/2] Remove dynahash.h All the callers of my_log2() are now limited to dynahash.c, so let's remove its header. This capability is provided by pg_bitutils.h already. --- src/backend/utils/hash/dynahash.c | 4 ++-- src/include/utils/dynahash.h | 20 -------------------- 2 files changed, 2 insertions(+), 22 deletions(-) delete mode 100644 src/include/utils/dynahash.h diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c index 1aeee5be42ac..ac94b9e93c6e 100644 --- a/src/backend/utils/hash/dynahash.c +++ b/src/backend/utils/hash/dynahash.c @@ -102,7 +102,6 @@ #include "port/pg_bitutils.h" #include "storage/shmem.h" #include "storage/spin.h" -#include "utils/dynahash.h" #include "utils/memutils.h" @@ -281,6 +280,7 @@ static bool init_htab(HTAB *hashp, int64 nelem); pg_noreturn static void hash_corrupted(HTAB *hashp); static uint32 hash_initial_lookup(HTAB *hashp, uint32 hashvalue, HASHBUCKET **bucketptr); +static int my_log2(int64 num); static int64 next_pow2_int64(int64 num); static int next_pow2_int(int64 num); static void register_seq_scan(HTAB *hashp); @@ -1813,7 +1813,7 @@ hash_corrupted(HTAB *hashp) } /* calculate ceil(log base 2) of num */ -int +static int my_log2(int64 num) { /* diff --git a/src/include/utils/dynahash.h b/src/include/utils/dynahash.h deleted file mode 100644 index a4362d3f65e5..000000000000 --- a/src/include/utils/dynahash.h +++ /dev/null @@ -1,20 +0,0 @@ -/*------------------------------------------------------------------------- - * - * dynahash.h - * POSTGRES dynahash.h file definitions - * - * - * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * IDENTIFICATION - * src/include/utils/dynahash.h - * - *------------------------------------------------------------------------- - */ -#ifndef DYNAHASH_H -#define DYNAHASH_H - -extern int my_log2(int64 num); - -#endif /* DYNAHASH_H */