summaryrefslogtreecommitdiffstats
path: root/debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--debian/patches-rt/net-Avoid-the-IPI-to-free-the.patch119
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,