[PATCH AUTOSEL 5.4 108/205] tipc: reduce sensitive to retransmit failures

From: Sasha Levin
Date: Thu Jan 16 2020 - 14:24:48 EST


From: Hoang Le <hoang.h.le@xxxxxxxxxxxxxx>

[ Upstream commit 426071f1f3995d7e9603246bffdcbf344cd31719 ]

With huge cluster (e.g >200nodes), the amount of that flow:
gap -> retransmit packet -> acked will take time in case of STATE_MSG
dropped/delayed because a lot of traffic. This lead to 1.5 sec tolerance
value criteria made link easy failure around 2nd, 3rd of failed
retransmission attempts.

Instead of re-introduced criteria of 99 faled retransmissions to fix the
issue, we increase failure detection timer to ten times tolerance value.

Fixes: 77cf8edbc0e7 ("tipc: simplify stale link failure criteria")
Acked-by: Jon Maloy <jon.maloy@xxxxxxxxxxxx>
Signed-off-by: Hoang Le <hoang.h.le@xxxxxxxxxxxxxx>
Acked-by: Jon
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/tipc/link.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 999eab592de8..a9d8a81e80cf 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1084,7 +1084,7 @@ static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
return false;

if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
- msecs_to_jiffies(r->tolerance)))
+ msecs_to_jiffies(r->tolerance * 10)))
return false;

hdr = buf_msg(skb);
--
2.20.1