[OPTIM] maintain_proxies: only wake up when the frontend will be ready

It's not needed to try to check the frontend's freq counter every
millisecond, we can precisely compute when to wake up.

diff --git a/src/proxy.c b/src/proxy.c
index 28bcfa01f1b25278981c34687c58f56b00d9aa77..420c1ab8c66b9f9bcea29a3bcdb9bd5a17442066 100644 (file)
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -383,10 +383,13 @@ void maintain_proxies(int *next)
                        if (p->fe_maxsps && read_freq_ctr(&p->fe_sess_per_sec) >= p->fe_maxsps) {
                                /* we're blocking because a limit was reached on the number of
                                 * requests/s on the frontend. We want to re-check ASAP, which
-                                * means in 1 ms because the timer will have settled down. Note
-                                * that we may already be in IDLE state here.
+                                * means in 1 ms before estimated expiration date, because the
+                                * timer will have settled down. Note that we may already be in
+                                * IDLE state here.
                                 */
-                               *next = tick_first(*next, tick_add(now_ms, 1));
+                               int wait = 1000 / p->fe_maxsps - 1;
+                               wait = MAX(wait, 1);
+                               *next = tick_first(*next, tick_add(now_ms, wait));
                                goto do_block;
                        }