[RFC net-next v3 3/9] net: napi: Make gro_flush_timeout per-NAPI
From: Joe Damato
Date: Thu Sep 12 2024 - 06:09:21 EST
Allow per-NAPI gro_flush_timeout setting.
The existing sysfs parameter is respected; writes to sysfs will write to
all NAPI structs for the device and the net_device gro_flush_timeout
field. Reads from sysfs will read from the net_device field.
The ability to set gro_flush_timeout on specific NAPI instances will be
added in a later commit, via netdev-genl.
Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
---
.../networking/net_cachelines/net_device.rst | 2 +-
include/linux/netdevice.h | 3 +-
net/core/dev.c | 12 +++---
net/core/dev.h | 39 +++++++++++++++++++
net/core/net-sysfs.c | 2 +-
5 files changed, 49 insertions(+), 9 deletions(-)
diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst
index eeeb7c925ec5..3d02ae79c850 100644
--- a/Documentation/networking/net_cachelines/net_device.rst
+++ b/Documentation/networking/net_cachelines/net_device.rst
@@ -98,7 +98,6 @@ struct_netdev_queue* _rx read_mostly
unsigned_int num_rx_queues
unsigned_int real_num_rx_queues - read_mostly get_rps_cpu
struct_bpf_prog* xdp_prog - read_mostly netif_elide_gro()
-unsigned_long gro_flush_timeout - read_mostly napi_complete_done
unsigned_int gro_max_size - read_mostly skb_gro_receive
unsigned_int gro_ipv4_max_size - read_mostly skb_gro_receive
rx_handler_func_t* rx_handler read_mostly - __netif_receive_skb_core
@@ -182,4 +181,5 @@ struct_devlink_port* devlink_port
struct_dpll_pin* dpll_pin
struct hlist_head page_pools
struct dim_irq_moder* irq_moder
+unsigned_long gro_flush_timeout
u32 napi_defer_hard_irqs
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f28b96c95259..3e07ab8e0295 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -377,6 +377,7 @@ struct napi_struct {
struct list_head dev_list;
struct hlist_node napi_hash_node;
int irq;
+ unsigned long gro_flush_timeout;
u32 defer_hard_irqs;
};
@@ -2075,7 +2076,6 @@ struct net_device {
int ifindex;
unsigned int real_num_rx_queues;
struct netdev_rx_queue *_rx;
- unsigned long gro_flush_timeout;
unsigned int gro_max_size;
unsigned int gro_ipv4_max_size;
rx_handler_func_t __rcu *rx_handler;
@@ -2398,6 +2398,7 @@ struct net_device {
/** @irq_moder: dim parameters used if IS_ENABLED(CONFIG_DIMLIB). */
struct dim_irq_moder *irq_moder;
+ unsigned long gro_flush_timeout;
u32 napi_defer_hard_irqs;
u8 priv[] ____cacheline_aligned
diff --git a/net/core/dev.c b/net/core/dev.c
index d3d0680664b3..f2fd503516de 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6220,12 +6220,12 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
if (work_done) {
if (n->gro_bitmask)
- timeout = READ_ONCE(n->dev->gro_flush_timeout);
+ timeout = napi_get_gro_flush_timeout(n);
n->defer_hard_irqs_count = napi_get_defer_hard_irqs(n);
}
if (n->defer_hard_irqs_count > 0) {
n->defer_hard_irqs_count--;
- timeout = READ_ONCE(n->dev->gro_flush_timeout);
+ timeout = napi_get_gro_flush_timeout(n);
if (timeout)
ret = false;
}
@@ -6360,7 +6360,7 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
if (flags & NAPI_F_PREFER_BUSY_POLL) {
napi->defer_hard_irqs_count = napi_get_defer_hard_irqs(napi);
- timeout = READ_ONCE(napi->dev->gro_flush_timeout);
+ timeout = napi_get_gro_flush_timeout(napi);
if (napi->defer_hard_irqs_count && timeout) {
hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
skip_schedule = true;
@@ -6642,6 +6642,7 @@ void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
napi->timer.function = napi_watchdog;
napi_set_defer_hard_irqs(napi, READ_ONCE(dev->napi_defer_hard_irqs));
+ napi_set_gro_flush_timeout(napi, READ_ONCE(dev->gro_flush_timeout));
init_gro_hash(napi);
napi->skb = NULL;
INIT_LIST_HEAD(&napi->rx_list);
@@ -11023,7 +11024,7 @@ void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
WARN_ON(dev->reg_state == NETREG_REGISTERED);
if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
- dev->gro_flush_timeout = 20000;
+ netdev_set_gro_flush_timeout(dev, 20000);
netdev_set_defer_hard_irqs(dev, 1);
}
}
@@ -11960,7 +11961,6 @@ static void __init net_dev_struct_check(void)
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ifindex);
CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, real_num_rx_queues);
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, 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);
@@ -11972,7 +11972,7 @@ 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, 100);
+ CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_rx, 92);
}
/*
diff --git a/net/core/dev.h b/net/core/dev.h
index f24fa38a2cac..a9d5f678564a 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -174,6 +174,45 @@ static inline void netdev_set_defer_hard_irqs(struct net_device *netdev,
napi_set_defer_hard_irqs(napi, defer);
}
+/**
+ * napi_get_gro_flush_timeout - get the gro_flush_timeout
+ * @n: napi struct to get the gro_flush_timeout from
+ *
+ * Return: the per-NAPI value of the gro_flush_timeout field.
+ */
+static inline unsigned long napi_get_gro_flush_timeout(const struct napi_struct *n)
+{
+ return READ_ONCE(n->gro_flush_timeout);
+}
+
+/**
+ * napi_set_gro_flush_timeout - set the gro_flush_timeout for a napi
+ * @n: napi struct to set the gro_flush_timeout
+ * @timeout: timeout value to set
+ *
+ * napi_set_gro_flush_timeout sets the per-NAPI gro_flush_timeout
+ */
+static inline void napi_set_gro_flush_timeout(struct napi_struct *n,
+ unsigned long timeout)
+{
+ WRITE_ONCE(n->gro_flush_timeout, timeout);
+}
+
+/**
+ * netdev_set_gro_flush_timeout - set gro_flush_timeout for all NAPIs of a netdev
+ * @netdev: the net_device for which all NAPIs will have their gro_flush_timeout set
+ * @timeout: the timeout value to set
+ */
+static inline void netdev_set_gro_flush_timeout(struct net_device *netdev,
+ unsigned long timeout)
+{
+ struct napi_struct *napi;
+
+ WRITE_ONCE(netdev->gro_flush_timeout, timeout);
+ list_for_each_entry(napi, &netdev->napi_list, dev_list)
+ napi_set_gro_flush_timeout(napi, timeout);
+}
+
int rps_cpumask_housekeeping(struct cpumask *mask);
#if defined(CONFIG_DEBUG_NET) && defined(CONFIG_BPF_SYSCALL)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 25125f356a15..2d9afc6e2161 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -409,7 +409,7 @@ NETDEVICE_SHOW_RW(tx_queue_len, fmt_dec);
static int change_gro_flush_timeout(struct net_device *dev, unsigned long val)
{
- WRITE_ONCE(dev->gro_flush_timeout, val);
+ netdev_set_gro_flush_timeout(dev, val);
return 0;
}
--
2.25.1