diff options
Diffstat (limited to 'debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch')
| -rw-r--r-- | debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch b/debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch new file mode 100644 index 000000000..5575db994 --- /dev/null +++ b/debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch @@ -0,0 +1,71 @@ +From 455243ba6a0787a8a8ed109e5af4e0cb42d90fbf Mon Sep 17 00:00:00 2001 +From: Priyanka Jain <Priyanka.Jain@freescale.com> +Date: Thu, 17 May 2012 09:35:11 +0530 +Subject: [PATCH 231/347] net: Remove preemption disabling in netif_rx() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +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 <Priyanka.Jain@freescale.com> +Acked-by: Rajan Srivastava <Rajan.Srivastava@freescale.com> +Cc: <rostedt@goodmis.orgn> +Link: http://lkml.kernel.org/r/1337227511-2271-1-git-send-email-Priyanka.Jain@freescale.com + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +--- + net/core/dev.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +diff --git a/net/core/dev.c b/net/core/dev.c +index e65dc7a7cc13..3df1fe052863 100644 +--- a/net/core/dev.c ++++ b/net/core/dev.c +@@ -4494,7 +4494,7 @@ static int netif_rx_internal(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); +@@ -4504,14 +4504,14 @@ static int netif_rx_internal(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; + } +-- +2.36.1 + |