Accommodate very large dshash tables.

nathan-bossart · nathan-bossart · commit 853cef097666 · 2024-12-17T15:24:45.000-06:00
If a dshash table grows very large (e.g., the dshash table for cumulative statistics when there are millions of tables), resizing it may fail with an error like: ERROR: invalid DSA memory alloc request size 1073741824 To fix, permit dshash resizing to allocate more than 1 GB by providing the DSA_ALLOC_HUGE flag. Reported-by: Andreas Scherbaum Author: Matthias van de Meent Reviewed-by: Cédric Villemain, Michael Paquier, Andres Freund Discussion: https://postgr.es/m/80a12d59-0d5e-4c54-866c-e69cd6536471%40pgug.de Backpatch-through: 13
diff --git a/src/backend/lib/dshash.c b/src/backend/lib/dshash.c
@@ -692,8 +692,10 @@ resize(dshash_table *hash_table, size_t new_size_log2)
 	Assert(new_size_log2 == hash_table->control->size_log2 + 1);
 
 	/* Allocate the space for the new table. */
-	new_buckets_shared = dsa_allocate0(hash_table->area,
-									   sizeof(dsa_pointer) * new_size);
+	new_buckets_shared =
+		dsa_allocate_extended(hash_table->area,
+							  sizeof(dsa_pointer) * new_size,
+							  DSA_ALLOC_HUGE | DSA_ALLOC_ZERO);
 	new_buckets = dsa_get_address(hash_table->area, new_buckets_shared);
 
 	/*
