[PATCH v3 2/2] net: add sysfs attribute for enabling threaded NAPI
From: Felix Fietkau <nbd@nbd.name>
Date: 2020-08-21 19:02:06
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This can be used to enable threaded NAPI on drivers that did not explicitly request it. Suggested-by: Eric Dumazet <redacted> Signed-off-by: Felix Fietkau <nbd@nbd.name> --- net/core/net-sysfs.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index efec66fa78b7..d7f7df715b60 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c@@ -472,6 +472,52 @@ static ssize_t proto_down_store(struct device *dev, } NETDEVICE_SHOW_RW(proto_down, fmt_dec); +static int change_napi_threaded(struct net_device *dev, unsigned long val) +{ + struct napi_struct *napi; + + if (list_empty(&dev->napi_list)) + return -EOPNOTSUPP; + + list_for_each_entry(napi, &dev->napi_list, dev_list) { + if (val) + set_bit(NAPI_STATE_THREADED, &napi->state); + else + clear_bit(NAPI_STATE_THREADED, &napi->state); + } + + return 0; +} + +static ssize_t napi_threaded_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + return netdev_store(dev, attr, buf, len, change_napi_threaded); +} + +static ssize_t napi_threaded_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct net_device *netdev = to_net_dev(dev); + struct napi_struct *napi; + bool enabled = false; + + if (!rtnl_trylock()) + return restart_syscall(); + + list_for_each_entry(napi, &netdev->napi_list, dev_list) { + if (test_bit(NAPI_STATE_THREADED, &napi->state)) + enabled = true; + } + + rtnl_unlock(); + + return sprintf(buf, fmt_dec, enabled); +} +static DEVICE_ATTR_RW(napi_threaded); + static ssize_t phys_port_id_show(struct device *dev, struct device_attribute *attr, char *buf) {
@@ -564,6 +610,7 @@ 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_napi_threaded.attr, &dev_attr_phys_port_id.attr, &dev_attr_phys_port_name.attr, &dev_attr_phys_switch_id.attr,
--
2.28.0