From a4cc7bd7a9c8e6e7638722cc1e1d85a5ceb58b6c Mon Sep 17 00:00:00 2001 From: Priyanka Jain Date: Thu, 17 May 2012 09:35:11 +0530 Subject: net,RT:REmove preemption disabling in netif_rx() 1)enqueue_to_backlog() (called from netif_rx) should be bind to a particluar CPU. This can be achieved by disabling migration. No need to disable preemption 2)Fixes crash "BUG: scheduling while atomic: ksoftirqd" in case of RT. If preemption is disabled, enqueue_to_backog() is called in atomic context. And if backlog exceeds its count, kfree_skb() is called. But in RT, kfree_skb() might gets scheduled out, so it expects non atomic context. 3)When CONFIG_PREEMPT_RT_FULL is not defined, migrate_enable(), migrate_disable() maps to preempt_enable() and preempt_disable(), so no change in functionality in case of non-RT. -Replace preempt_enable(), preempt_disable() with migrate_enable(), migrate_disable() respectively -Replace get_cpu(), put_cpu() with get_cpu_light(), put_cpu_light() respectively Signed-off-by: Priyanka Jain Acked-by: Rajan Srivastava Cc: Link: http://lkml.kernel.org/r/1337227511-2271-1-git-send-email-Priyanka.Jain@freescale.com Cc: stable-rt@vger.kernel.org Signed-off-by: Thomas Gleixner diff --git a/net/core/dev.c b/net/core/dev.c index e1b5ef2..aa529f7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3091,7 +3091,7 @@ int netif_rx(struct sk_buff *skb) struct rps_dev_flow voidflow, *rflow = &voidflow; int cpu; - preempt_disable(); + migrate_disable(); rcu_read_lock(); cpu = get_rps_cpu(skb->dev, skb, &rflow); @@ -3101,13 +3101,13 @@ int netif_rx(struct sk_buff *skb) ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); rcu_read_unlock(); - preempt_enable(); + migrate_enable(); } else #endif { unsigned int qtail; - ret = enqueue_to_backlog(skb, get_cpu(), &qtail); - put_cpu(); + ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail); + put_cpu_light(); } return ret; } -- cgit v0.10.2