From 78021ee9ef31dfb7055701b712694feecef238e3 Mon Sep 17 00:00:00 2001 From: Christopher Faulet Date: Thu, 9 Nov 2023 09:54:51 +0100 Subject: [PATCH] BUG/MEDIUM: stconn: Don't update stream expiration date if already expired The commit 08d7169f4 ("MINOR: stconn: Don't queue stream task in past in sc_notify()") tried to fix issues with epiration date set in past for the stream in sc_notify(). However it remains some cases where the stream expiration date may already be expired before recomputing it. This happens when an event is reported by the mux exactly when a timeout is triggered. In this case, depending on the scheduling, the SC may be woken up before the stream. For these cases, we fall into the BUG_ON() preventing to queue in the past. So, it remains unexpected to queue a task in the past. The BUG_ON() is correct at this place. We must just avoid to recompute the stream expiration date if it is already expired. At worst, the stream will be woken up for nothing. But it is not really a big deal because it will only happen on timeouts from time to time. It is so sporadic that we can ignore it from a performance point of view. This patch must be backpoted to 2.8. Be careful to remove the BUG_ON() on the 2.8. --- src/stconn.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/src/stconn.c b/src/stconn.c index 8ced6b8dd..d6e4683d4 100644 --- a/src/stconn.c +++ b/src/stconn.c @@ -1135,19 +1135,20 @@ static void sc_notify(struct stconn *sc) task_wakeup(task, TASK_WOKEN_IO); } else { - /* Update expiration date for the task and requeue it */ - task->expire = (tick_is_expired(task->expire, now_ms) ? 0 : task->expire); - task->expire = tick_first(task->expire, sc_ep_rcv_ex(sc)); - task->expire = tick_first(task->expire, sc_ep_snd_ex(sc)); - task->expire = tick_first(task->expire, sc_ep_rcv_ex(sco)); - task->expire = tick_first(task->expire, sc_ep_snd_ex(sco)); - task->expire = tick_first(task->expire, ic->analyse_exp); - task->expire = tick_first(task->expire, oc->analyse_exp); - task->expire = tick_first(task->expire, __sc_strm(sc)->conn_exp); + /* Update expiration date for the task and requeue it if not already expired */ + if (!tick_is_expired(task->expire, now_ms)) { + task->expire = tick_first(task->expire, sc_ep_rcv_ex(sc)); + task->expire = tick_first(task->expire, sc_ep_snd_ex(sc)); + task->expire = tick_first(task->expire, sc_ep_rcv_ex(sco)); + task->expire = tick_first(task->expire, sc_ep_snd_ex(sco)); + task->expire = tick_first(task->expire, ic->analyse_exp); + task->expire = tick_first(task->expire, oc->analyse_exp); + task->expire = tick_first(task->expire, __sc_strm(sc)->conn_exp); - /* WARNING: Don't forget to remove this BUG_ON before 2.9.0 */ - BUG_ON(tick_is_expired(task->expire, now_ms)); - task_queue(task); + /* WARNING: Don't forget to remove this BUG_ON before 2.9.0 */ + BUG_ON(tick_is_expired(task->expire, now_ms)); + task_queue(task); + } } if (ic->flags & CF_READ_EVENT)