From 4cb54876e7afb4d257b1833e484c0d189c60d645 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat, 27 May 2017 19:02:06 +0200
Subject: [PATCH 132/518] net/core: disable NET_RX_BUSY_POLL
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sk_busy_loop() does preempt_disable() followed by a few operations which can
take sleeping locks and may get long.
I _think_ that we could use preempt_disable_nort() (in sk_busy_loop()) instead
but after a successfull cmpxchg(&napi->state, …) we would gain the ressource
and could be scheduled out. At this point nobody knows who (which context) owns
it and so it could take a while until the state is realeased and napi_poll()
could be invoked again.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 net/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/Kconfig b/net/Kconfig
index 9dba2715919d7..9c7b38379c099 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -272,7 +272,7 @@ config CGROUP_NET_CLASSID
 
 config NET_RX_BUSY_POLL
 	bool
-	default y
+	default y if !PREEMPT_RT_FULL
 
 config BQL
 	bool
-- 
2.41.0

