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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches-rt/0231-net-Remove-preemption-disabling-in-netif_rx.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-08b74a000942a380fe028845f92cd3a0dee827d5.tar.xz
linux-08b74a000942a380fe028845f92cd3a0dee827d5.zip
Adding debian version 4.19.249-2.debian/4.19.249-2debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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.patch71
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
+