From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 16 Jun 2017 19:03:16 +0200
Subject: [PATCH] net/core: use local_bh_disable() in netif_rx_ni()
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: da77ceac3d20f27310a07a7c346a4ee6b40d6c28
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
In 2004 netif_rx_ni() gained a preempt_disable() section around
netif_rx() and its do_softirq() + testing for it. The do_softirq() part
is required because netif_rx() raises the softirq but does not invoke
it. The preempt_disable() is required to remain on the same CPU which added the
skb to the per-CPU list.
All this can be avoided be putting this into a local_bh_disable()ed
section. The local_bh_enable() part will invoke do_softirq() if
required.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
net/core/dev.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4691,11 +4691,9 @@ int netif_rx_ni(struct sk_buff *skb)
trace_netif_rx_ni_entry(skb);
- preempt_disable();
+ local_bh_disable();
err = netif_rx_internal(skb);
- if (local_softirq_pending())
- do_softirq();
- preempt_enable();
+ local_bh_enable();
trace_netif_rx_ni_exit(err);
return err;