diff options
Diffstat (limited to 'debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch')
| -rw-r--r-- | debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch b/debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch deleted file mode 100644 index 70bfac405a..0000000000 --- a/debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch +++ /dev/null @@ -1,119 +0,0 @@ -From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Date: Mon, 15 Aug 2022 17:29:50 +0200 -Subject: [PATCH] net: Avoid the IPI to free the -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.7/older/patches-6.7-rt6.tar.xz - -skb_attempt_defer_free() collects a skbs, which was allocated on a -remote CPU, on a per-CPU list. These skbs are either freed on that -remote CPU once the CPU enters NET_RX or an remote IPI function is -invoked in to raise the NET_RX softirq if a threshold of pending skb has -been exceeded. -This remote IPI can cause the wakeup of ksoftirqd on PREEMPT_RT if the -remote CPU idle was idle. This is undesired because once the ksoftirqd -is running it will acquire all pending softirqs and they will not be -executed as part of the threaded interrupt until ksoftird goes idle -again. - -To void all this, schedule the deferred clean up from a worker. - -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> ---- - include/linux/netdevice.h | 4 ++++ - net/core/dev.c | 39 ++++++++++++++++++++++++++++++--------- - net/core/skbuff.c | 7 ++++++- - 3 files changed, 40 insertions(+), 10 deletions(-) - ---- a/include/linux/netdevice.h -+++ b/include/linux/netdevice.h -@@ -3288,7 +3288,11 @@ struct softnet_data { - int defer_count; - int defer_ipi_scheduled; - struct sk_buff *defer_list; -+#ifndef CONFIG_PREEMPT_RT - call_single_data_t defer_csd; -+#else -+ struct work_struct defer_work; -+#endif - }; - - static inline void input_queue_head_incr(struct softnet_data *sd) ---- a/net/core/dev.c -+++ b/net/core/dev.c -@@ -4679,15 +4679,6 @@ static void rps_trigger_softirq(void *da - - #endif /* CONFIG_RPS */ - --/* Called from hardirq (IPI) context */ --static void trigger_rx_softirq(void *data) --{ -- struct softnet_data *sd = data; -- -- __raise_softirq_irqoff(NET_RX_SOFTIRQ); -- smp_store_release(&sd->defer_ipi_scheduled, 0); --} -- - /* - * After we queued a packet into sd->input_pkt_queue, - * we need to make sure this queue is serviced soon. -@@ -6658,6 +6649,32 @@ static void skb_defer_free_flush(struct - } - } - -+#ifndef CONFIG_PREEMPT_RT -+ -+/* Called from hardirq (IPI) context */ -+static void trigger_rx_softirq(void *data) -+{ -+ struct softnet_data *sd = data; -+ -+ __raise_softirq_irqoff(NET_RX_SOFTIRQ); -+ smp_store_release(&sd->defer_ipi_scheduled, 0); -+} -+ -+#else -+ -+static void trigger_rx_softirq(struct work_struct *defer_work) -+{ -+ struct softnet_data *sd; -+ -+ sd = container_of(defer_work, struct softnet_data, defer_work); -+ smp_store_release(&sd->defer_ipi_scheduled, 0); -+ local_bh_disable(); -+ skb_defer_free_flush(sd); -+ local_bh_enable(); -+} -+ -+#endif -+ - static int napi_threaded_poll(void *data) - { - struct napi_struct *napi = data; -@@ -11621,7 +11638,11 @@ static int __init net_dev_init(void) - INIT_CSD(&sd->csd, rps_trigger_softirq, sd); - sd->cpu = i; - #endif -+#ifndef CONFIG_PREEMPT_RT - INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd); -+#else -+ INIT_WORK(&sd->defer_work, trigger_rx_softirq); -+#endif - spin_lock_init(&sd->defer_lock); - - init_gro_hash(&sd->backlog); ---- a/net/core/skbuff.c -+++ b/net/core/skbuff.c -@@ -6858,8 +6858,13 @@ nodefer: __kfree_skb(skb); - /* Make sure to trigger NET_RX_SOFTIRQ on the remote CPU - * if we are unlucky enough (this seems very unlikely). - */ -- if (unlikely(kick) && !cmpxchg(&sd->defer_ipi_scheduled, 0, 1)) -+ if (unlikely(kick) && !cmpxchg(&sd->defer_ipi_scheduled, 0, 1)) { -+#ifndef CONFIG_PREEMPT_RT - smp_call_function_single_async(cpu, &sd->defer_csd); -+#else -+ schedule_work_on(cpu, &sd->defer_work); -+#endif -+ } - } - - static void skb_splice_csum_page(struct sk_buff *skb, struct page *page, |