From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Sat, 20 Jan 2018 19:23:43 +0000 (-0700)
Subject: Move to dynamically allocated redundant state
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=276992d5ff9aeb899bb0af78edc95f8a0f1d53d4;p=thirdparty%2Ffreeradius-server.git

Move to dynamically allocated redundant state

With the static states gone the stack should be much smaller.  The foreach state removed the stack for each request is now 4K smaller, which is non-negligable when you're dealing with 100s of thousands of requests.
---

diff --git a/src/main/unlang_op.c b/src/main/unlang_op.c
index 8d27d6ce4e7..5949dc52348 100644
--- a/src/main/unlang_op.c
+++ b/src/main/unlang_op.c
@@ -108,9 +108,10 @@ static uint64_t unlang_active_callers(unlang_t *instruction)
 static unlang_action_t unlang_load_balance(REQUEST *request,
 					   rlm_rcode_t *presult, UNUSED int *priority)
 {
-	unlang_stack_t		*stack = request->stack;
-	unlang_stack_frame_t	*frame = &stack->frame[stack->depth];
-	unlang_t		*instruction = frame->instruction;
+	unlang_stack_t			*stack = request->stack;
+	unlang_stack_frame_t		*frame = &stack->frame[stack->depth];
+	unlang_t			*instruction = frame->instruction;
+	unlang_frame_state_redundant_t	*redundant;
 	unlang_group_t		*g;
 
 	uint32_t count = 0;
@@ -125,6 +126,8 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 	if (!frame->repeat) {
 		RDEBUG4("%s setting up", frame->instruction->debug_name);
 
+		frame->state = redundant = talloc_zero(stack, unlang_frame_state_redundant_t);
+
 		if (g->vpt) {
 			uint32_t hash, start;
 			ssize_t slen;
@@ -184,12 +187,12 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 			RDEBUG3("load-balance starting at child %d", (int) start);
 
 			count = 0;
-			for (frame->redundant.child = frame->redundant.found = g->children;
-			     frame->redundant.child != NULL;
-			     frame->redundant.child = frame->redundant.child->next) {
+			for (redundant->child = redundant->found = g->children;
+			     redundant->child != NULL;
+			     redundant->child = redundant->child->next) {
 				count++;
 				if (count == start) {
-					frame->redundant.found = frame->redundant.child;
+					redundant->found = redundant->child;
 					break;
 				}
 			}
@@ -204,11 +207,11 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 			/*
 			 *	Choose a child at random.
 			 */
-			for (frame->redundant.child = frame->redundant.found = g->children, num = 0;
-			     frame->redundant.child != NULL;
-			     frame->redundant.child = frame->redundant.child->next, num++) {
+			for (redundant->child = redundant->found = g->children, num = 0;
+			     redundant->child != NULL;
+			     redundant->child = redundant->child->next, num++) {
 				uint64_t active_callers;
-				unlang_t *child = frame->redundant.child;
+				unlang_t *child = redundant->child;
 
 				if (child->type != UNLANG_TYPE_MODULE_CALL) {
 					active_callers = unlang_active_callers(child);
@@ -240,7 +243,7 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 
 					count = 1;
 					lowest_active_callers = active_callers;
-					frame->redundant.found = frame->redundant.child;
+					redundant->found = redundant->child;
 					continue;
 				}
 
@@ -259,23 +262,24 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 
 				if ((count * (fr_rand() & 0xffff)) < (uint32_t) 0x10000) {
 					RDEBUG3("load-balance choosing random child %d", num);
-					frame->redundant.found = frame->redundant.child;
+					redundant->found = redundant->child;
 				}
 			}
 		}
 
 		if (instruction->type == UNLANG_TYPE_LOAD_BALANCE) {
-			unlang_push(stack, frame->redundant.found, frame->result, UNLANG_NEXT_STOP, UNLANG_SUB_FRAME);
+			unlang_push(stack, redundant->found, frame->result, UNLANG_NEXT_STOP, UNLANG_SUB_FRAME);
 			return UNLANG_ACTION_PUSHED_CHILD;
 		}
 
 		/*
 		 *	redundant-load-balance starts at this one.
 		 */
-		frame->redundant.child = frame->redundant.found;
+		redundant->child = redundant->found;
 
 	} else {
 		RDEBUG4("%s resuming", frame->instruction->debug_name);
+		redundant = talloc_get_type_abort(frame->state, unlang_frame_state_redundant_t);
 
 		/*
 		 *	We are in a resumed frame.  The module we
@@ -288,7 +292,7 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 		/*
 		 *	We were called again.  See if we're done.
 		 */
-		if (frame->redundant.child->actions[*presult] == MOD_ACTION_RETURN) {
+		if (redundant->child->actions[*presult] == MOD_ACTION_RETURN) {
 			return UNLANG_ACTION_CALCULATE_RESULT;
 		}
 
@@ -301,10 +305,10 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 		 *	uint64_t and bit mask for simplicity.
 		 */
 
-		frame->redundant.child = frame->redundant.child->next;
-		if (!frame->redundant.child) frame->redundant.child = g->children;
+		redundant->child = redundant->child->next;
+		if (!redundant->child) redundant->child = g->children;
 
-		if (frame->redundant.child == frame->redundant.found) {
+		if (redundant->child == redundant->found) {
 			return UNLANG_ACTION_CALCULATE_RESULT;
 		}
 	}
@@ -312,7 +316,7 @@ static unlang_action_t unlang_load_balance(REQUEST *request,
 	/*
 	 *	Push the child, and yield for a later return.
 	 */
-	unlang_push(stack, frame->redundant.child, frame->result, UNLANG_NEXT_STOP, UNLANG_SUB_FRAME);
+	unlang_push(stack, redundant->child, frame->result, UNLANG_NEXT_STOP, UNLANG_SUB_FRAME);
 	frame->repeat = true;
 
 	return UNLANG_ACTION_PUSHED_CHILD;
diff --git a/src/main/unlang_priv.h b/src/main/unlang_priv.h
index 2a5f3319953..b5b2bee8ab7 100644
--- a/src/main/unlang_priv.h
+++ b/src/main/unlang_priv.h
@@ -289,10 +289,6 @@ typedef struct {
 	bool			repeat : 1;			//!< Call the action callback again on our way
 								//!< back up the stack.
 	bool			top_frame : 1;			//!< are we the top frame of the stack?
-
-	union {
-		unlang_frame_state_redundant_t	redundant;	//!< Redundant section state.
-	};
 } unlang_stack_frame_t;
 
 /** An unlang stack associated with a request