Re: [PATCH v3 13/13] flow: Avoid moving flow entries to compact table

2 Jan 2024


      On Mon, 1 Jan 2024 21:44:54 +1100
David Gibson  wrote:
...
On Thu, Dec 28, 2023 at 07:25:25PM +0100, Stefano Brivio wrote:
...
On Thu, 21 Dec 2023 17:15:49 +1100
David Gibson  wrote:
[...]
...
void flow_defer_handler(const struct ctx *c, const struct timespec *now)
 {
+	struct flow_free_block *free_head = NULL;
+	unsigned *last_next = &flow_first_free;
  bool timer = false;
-	union flow *flow;
+	unsigned idx;
if (timespec_diff_ms(now, &flow_timer_run) >= FLOW_TIMER_INTERVAL) {
      timer = true;
      flow_timer_run = *now;
  }
-	for (flow = flowtab + flow_count - 1; flow >= flowtab; flow--) {
+	for (idx = 0; idx < FLOW_MAX; idx++) {
+		union flow *flow = &flowtab[idx];
      bool closed = false;
+		if (flow->f.type == FLOW_TYPE_NONE) {
+			/* Start of a free block */
+			free_head = &flow->free;
+			*last_next = idx;
+			last_next = &free_head->next;
+			/* Skip the rest of the block */
+			idx += free_head->n - 1;
+			continue;
+		}
+
+
Stray tabs.
...
switch (flow->f.type) {
+		case FLOW_TYPE_NONE:
+			closed = true;
+			break;
...more important than stray tabs, I noticed only now: how would we ever
hit this switch case, if you're checking for this in the if clause just
before?
...
...
...
case FLOW_TCP:
      	closed = tcp_flow_defer(flow);
      	break;
-- 
Stefano