diff --git a/contrib/pg_trgm/trgm_regexp.c b/contrib/pg_trgm/trgm_regexp.c
index 64816dd370..1887a39161 100644
--- a/contrib/pg_trgm/trgm_regexp.c
+++ b/contrib/pg_trgm/trgm_regexp.c
@@ -907,6 +907,7 @@ transformGraph(TrgmNFA *trgmNFA)
 	HASHCTL		hashCtl;
 	TrgmStateKey initkey;
 	TrgmState  *initstate;
+	ListCell   *lc;
 
 	/* Initialize this stage's workspace in trgmNFA struct */
 	trgmNFA->queue = NIL;
@@ -937,12 +938,13 @@ transformGraph(TrgmNFA *trgmNFA)
 	/*
 	 * Recursively build the expanded graph by processing queue of states
 	 * (breadth-first search).  getState already put initstate in the queue.
+	 * Note that getState will append new states to the queue within the loop,
+	 * too; this works as long as we don't do repeat fetches using the "lc"
+	 * pointer.
 	 */
-	while (trgmNFA->queue != NIL)
+	foreach(lc, trgmNFA->queue)
 	{
-		TrgmState  *state = (TrgmState *) linitial(trgmNFA->queue);
-
-		trgmNFA->queue = list_delete_first(trgmNFA->queue);
+		TrgmState  *state = (TrgmState *) lfirst(lc);
 
 		/*
 		 * If we overflowed then just mark state as final.  Otherwise do
@@ -966,22 +968,29 @@ transformGraph(TrgmNFA *trgmNFA)
 static void
 processState(TrgmNFA *trgmNFA, TrgmState *state)
 {
+	ListCell   *lc;
+
 	/* keysQueue should be NIL already, but make sure */
 	trgmNFA->keysQueue = NIL;
 
 	/*
 	 * Add state's own key, and then process all keys added to keysQueue until
-	 * queue is empty.  But we can quit if the state gets marked final.
+	 * queue is finished.  But we can quit if the state gets marked final.
 	 */
 	addKey(trgmNFA, state, &state->stateKey);
-	while (trgmNFA->keysQueue != NIL && !(state->flags & TSTATE_FIN))
+	foreach(lc, trgmNFA->keysQueue)
 	{
-		TrgmStateKey *key = (TrgmStateKey *) linitial(trgmNFA->keysQueue);
+		TrgmStateKey *key = (TrgmStateKey *) lfirst(lc);
 
-		trgmNFA->keysQueue = list_delete_first(trgmNFA->keysQueue);
+		if (state->flags & TSTATE_FIN)
+			break;
 		addKey(trgmNFA, state, key);
 	}
 
+	/* Release keysQueue to clean up for next cycle */
+	list_free(trgmNFA->keysQueue);
+	trgmNFA->keysQueue = NIL;
+
 	/*
 	 * Add outgoing arcs only if state isn't final (we have no interest in
 	 * outgoing arcs if we already match)
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index c99a0de4dd..f5a187cae3 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -2584,8 +2584,9 @@ agg_refill_hash_table(AggState *aggstate)
 	if (aggstate->hash_batches == NIL)
 		return false;
 
-	batch = linitial(aggstate->hash_batches);
-	aggstate->hash_batches = list_delete_first(aggstate->hash_batches);
+	/* hash_batches is a stack, with the top item at the end of the list */
+	batch = llast(aggstate->hash_batches);
+	aggstate->hash_batches = list_delete_last(aggstate->hash_batches);
 
 	hash_agg_set_limits(aggstate->hashentrysize, batch->input_card,
 						batch->used_bits, &aggstate->hash_mem_limit,
@@ -3098,7 +3099,7 @@ hashagg_spill_finish(AggState *aggstate, HashAggSpill *spill, int setno)
 		new_batch = hashagg_batch_new(tape, setno,
 									  spill->ntuples[i], cardinality,
 									  used_bits);
-		aggstate->hash_batches = lcons(new_batch, aggstate->hash_batches);
+		aggstate->hash_batches = lappend(aggstate->hash_batches, new_batch);
 		aggstate->hash_batches_used++;
 	}
 
@@ -3113,8 +3114,6 @@ hashagg_spill_finish(AggState *aggstate, HashAggSpill *spill, int setno)
 static void
 hashagg_reset_spill_state(AggState *aggstate)
 {
-	ListCell   *lc;
-
 	/* free spills from initial pass */
 	if (aggstate->hash_spills != NULL)
 	{
@@ -3132,13 +3131,7 @@ hashagg_reset_spill_state(AggState *aggstate)
 	}
 
 	/* free batches */
-	foreach(lc, aggstate->hash_batches)
-	{
-		HashAggBatch *batch = (HashAggBatch *) lfirst(lc);
-
-		pfree(batch);
-	}
-	list_free(aggstate->hash_batches);
+	list_free_deep(aggstate->hash_batches);
 	aggstate->hash_batches = NIL;
 
 	/* close tape set */
diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c
index 169dad96d7..fb29449573 100644
--- a/src/backend/jit/llvm/llvmjit.c
+++ b/src/backend/jit/llvm/llvmjit.c
@@ -171,6 +171,7 @@ static void
 llvm_release_context(JitContext *context)
 {
 	LLVMJitContext *llvm_context = (LLVMJitContext *) context;
+	ListCell   *lc;
 
 	/*
 	 * When this backend is exiting, don't clean up LLVM. As an error might
@@ -188,12 +189,9 @@ llvm_release_context(JitContext *context)
 		llvm_context->module = NULL;
 	}
 
-	while (llvm_context->handles != NIL)
+	foreach(lc, llvm_context->handles)
 	{
-		LLVMJitHandle *jit_handle;
-
-		jit_handle = (LLVMJitHandle *) linitial(llvm_context->handles);
-		llvm_context->handles = list_delete_first(llvm_context->handles);
+		LLVMJitHandle *jit_handle = (LLVMJitHandle *) lfirst(lc);
 
 #if LLVM_VERSION_MAJOR > 11
 		{
@@ -221,6 +219,8 @@ llvm_release_context(JitContext *context)
 
 		pfree(jit_handle);
 	}
+	list_free(llvm_context->handles);
+	llvm_context->handles = NIL;
 }
 
 /*