From: Martin Karsten <mkarsten@xxxxxxxxxxxx>
This patch doesn't change any behavior but prepares the code for other
changes in the following commits which use irq_suspend_timeout as a
timeout for IRQ suspension.
Signed-off-by: Martin Karsten <mkarsten@xxxxxxxxxxxx>
Co-developed-by: Joe Damato <jdamato@xxxxxxxxxx>
Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
Tested-by: Joe Damato <jdamato@xxxxxxxxxx>
Tested-by: Martin Karsten <mkarsten@xxxxxxxxxxxx>
---
Documentation/networking/napi.rst | 3 +++
include/linux/netdevice.h | 2 ++
net/core/dev.c | 3 ++-
net/core/net-sysfs.c | 18 ++++++++++++++++++
4 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/Documentation/networking/napi.rst b/Documentation/networking/napi.rst
index 7bf7b95c4f7a..0a029dd6d77e 100644
--- a/Documentation/networking/napi.rst
+++ b/Documentation/networking/napi.rst
@@ -192,6 +192,9 @@ The ``gro_flush_timeout`` sysfs configuration of the netdevice
is reused to control the delay of the timer, while
``napi_defer_hard_irqs`` controls the number of consecutive empty polls
before NAPI gives up and goes back to using hardware IRQs.
+``irq_suspend_timeout`` is used to determine how long an application can
+completely suspend IRQs. It is used in combination with SO_PREFER_BUSY_POLL,
+which can be set on a per-epoll context basis with EPIOCSPARAMS ioctl.
.. _poll:
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0ef3eaa23f4b..31867bb2ff65 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1857,6 +1857,7 @@ enum netdev_reg_state {
* @gro_flush_timeout: timeout for GRO layer in NAPI
* @napi_defer_hard_irqs: If not zero, provides a counter that would
* allow to avoid NIC hard IRQ, on busy queues.
+ * @irq_suspend_timeout: IRQ suspension timeout
*
* @rx_handler: handler for received packets
* @rx_handler_data: XXX: need comments on this one
@@ -2060,6 +2061,7 @@ struct net_device {
struct netdev_rx_queue *_rx;
unsigned long gro_flush_timeout;
int napi_defer_hard_irqs;
+ unsigned long irq_suspend_timeout;
unsigned int gro_max_size;
unsigned int gro_ipv4_max_size;
rx_handler_func_t __rcu *rx_handler;
diff --git a/net/core/dev.c b/net/core/dev.c
index 751d9b70e6ad..bf45c90aebcd 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11937,6 +11937,7 @@ static void __init net_dev_struct_check(void)
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, _rx);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_flush_timeout);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, napi_defer_hard_irqs);
+ CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, irq_suspend_timeout);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_max_size);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, gro_ipv4_max_size);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, rx_handler);
@@ -11948,7 +11949,7 @@ static void __init net_dev_struct_check(void)
#ifdef CONFIG_NET_XGRESS
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, tcx_ingress);
#endif
- CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_rx, 104);
+ CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_rx, 112);
}
/*
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 0e2084ce7b75..fb6f3327310f 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -440,6 +440,23 @@ static ssize_t napi_defer_hard_irqs_store(struct device *dev,
}
NETDEVICE_SHOW_RW(napi_defer_hard_irqs, fmt_dec);
+static int change_irq_suspend_timeout(struct net_device *dev, unsigned long val)
+{
+ WRITE_ONCE(dev->irq_suspend_timeout, val);
+ return 0;
+}
+
+static ssize_t irq_suspend_timeout_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ return netdev_store(dev, attr, buf, len, change_irq_suspend_timeout);
+}
+NETDEVICE_SHOW_RW(irq_suspend_timeout, fmt_ulong);
+
static ssize_t ifalias_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
@@ -664,6 +681,7 @@ static struct attribute *net_class_attrs[] __ro_after_init = {
&dev_attr_tx_queue_len.attr,
&dev_attr_gro_flush_timeout.attr,
&dev_attr_napi_defer_hard_irqs.attr,
+ &dev_attr_irq_suspend_timeout.attr,
&dev_attr_phys_port_id.attr,
&dev_attr_phys_port_name.attr,
&dev_attr_phys_switch_id.attr,
--
2.25.1
