diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/602-v5.12-net-add-sysfs-attribute-to-control-napi-threaded-mod.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/602-v5.12-net-add-sysfs-attribute-to-control-napi-threaded-mod.patch | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/target/linux/generic/backport-5.4/602-v5.12-net-add-sysfs-attribute-to-control-napi-threaded-mod.patch b/target/linux/generic/backport-5.4/602-v5.12-net-add-sysfs-attribute-to-control-napi-threaded-mod.patch deleted file mode 100644 index bdc34a15ea..0000000000 --- a/target/linux/generic/backport-5.4/602-v5.12-net-add-sysfs-attribute-to-control-napi-threaded-mod.patch +++ /dev/null @@ -1,177 +0,0 @@ -From: Wei Wang <weiwan@google.com> -Date: Mon, 8 Feb 2021 11:34:10 -0800 -Subject: [PATCH] net: add sysfs attribute to control napi threaded mode - -This patch adds a new sysfs attribute to the network device class. -Said attribute provides a per-device control to enable/disable the -threaded mode for all the napi instances of the given network device, -without the need for a device up/down. -User sets it to 1 or 0 to enable or disable threaded mode. -Note: when switching between threaded and the current softirq based mode -for a napi instance, it will not immediately take effect if the napi is -currently being polled. The mode switch will happen for the next time -napi_schedule() is called. - -Co-developed-by: Paolo Abeni <pabeni@redhat.com> -Signed-off-by: Paolo Abeni <pabeni@redhat.com> -Co-developed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> -Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> -Co-developed-by: Felix Fietkau <nbd@nbd.name> -Signed-off-by: Felix Fietkau <nbd@nbd.name> -Signed-off-by: Wei Wang <weiwan@google.com> -Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> -Signed-off-by: David S. Miller <davem@davemloft.net> ---- - ---- a/Documentation/ABI/testing/sysfs-class-net -+++ b/Documentation/ABI/testing/sysfs-class-net -@@ -301,3 +301,18 @@ Contact: netdev@vger.kernel.org - Description: - 32-bit unsigned integer counting the number of times the link has - been down -+ -+What: /sys/class/net/<iface>/threaded -+Date: Jan 2021 -+KernelVersion: 5.12 -+Contact: netdev@vger.kernel.org -+Description: -+ Boolean value to control the threaded mode per device. User could -+ set this value to enable/disable threaded mode for all napi -+ belonging to this device, without the need to do device up/down. -+ -+ Possible values: -+ == ================================== -+ 0 threaded mode disabled for this dev -+ 1 threaded mode enabled for this dev -+ == ================================== ---- a/include/linux/netdevice.h -+++ b/include/linux/netdevice.h -@@ -498,6 +498,8 @@ static inline bool napi_complete(struct - */ - bool napi_hash_del(struct napi_struct *napi); - -+int dev_set_threaded(struct net_device *dev, bool threaded); -+ - /** - * napi_disable - prevent NAPI from scheduling - * @n: NAPI context ---- a/net/core/dev.c -+++ b/net/core/dev.c -@@ -3914,8 +3914,9 @@ static inline void ____napi_schedule(str - - if (test_bit(NAPI_STATE_THREADED, &napi->state)) { - /* Paired with smp_mb__before_atomic() in -- * napi_enable(). Use READ_ONCE() to guarantee -- * a complete read on napi->thread. Only call -+ * napi_enable()/dev_set_threaded(). -+ * Use READ_ONCE() to guarantee a complete -+ * read on napi->thread. Only call - * wake_up_process() when it's not NULL. - */ - thread = READ_ONCE(napi->thread); -@@ -6293,6 +6294,49 @@ static void init_gro_hash(struct napi_st - napi->gro_bitmask = 0; - } - -+int dev_set_threaded(struct net_device *dev, bool threaded) -+{ -+ struct napi_struct *napi; -+ int err = 0; -+ -+ if (dev->threaded == threaded) -+ return 0; -+ -+ if (threaded) { -+ list_for_each_entry(napi, &dev->napi_list, dev_list) { -+ if (!napi->thread) { -+ err = napi_kthread_create(napi); -+ if (err) { -+ threaded = false; -+ break; -+ } -+ } -+ } -+ } -+ -+ dev->threaded = threaded; -+ -+ /* Make sure kthread is created before THREADED bit -+ * is set. -+ */ -+ smp_mb__before_atomic(); -+ -+ /* Setting/unsetting threaded mode on a napi might not immediately -+ * take effect, if the current napi instance is actively being -+ * polled. In this case, the switch between threaded mode and -+ * softirq mode will happen in the next round of napi_schedule(). -+ * This should not cause hiccups/stalls to the live traffic. -+ */ -+ list_for_each_entry(napi, &dev->napi_list, dev_list) { -+ if (threaded) -+ set_bit(NAPI_STATE_THREADED, &napi->state); -+ else -+ clear_bit(NAPI_STATE_THREADED, &napi->state); -+ } -+ -+ return err; -+} -+ - void netif_napi_add(struct net_device *dev, struct napi_struct *napi, - int (*poll)(struct napi_struct *, int), int weight) - { ---- a/net/core/net-sysfs.c -+++ b/net/core/net-sysfs.c -@@ -557,6 +557,45 @@ static ssize_t phys_switch_id_show(struc - } - static DEVICE_ATTR_RO(phys_switch_id); - -+static ssize_t threaded_show(struct device *dev, -+ struct device_attribute *attr, char *buf) -+{ -+ struct net_device *netdev = to_net_dev(dev); -+ ssize_t ret = -EINVAL; -+ -+ if (!rtnl_trylock()) -+ return restart_syscall(); -+ -+ if (dev_isalive(netdev)) -+ ret = sprintf(buf, fmt_dec, netdev->threaded); -+ -+ rtnl_unlock(); -+ return ret; -+} -+ -+static int modify_napi_threaded(struct net_device *dev, unsigned long val) -+{ -+ int ret; -+ -+ if (list_empty(&dev->napi_list)) -+ return -EOPNOTSUPP; -+ -+ if (val != 0 && val != 1) -+ return -EOPNOTSUPP; -+ -+ ret = dev_set_threaded(dev, val); -+ -+ return ret; -+} -+ -+static ssize_t threaded_store(struct device *dev, -+ struct device_attribute *attr, -+ const char *buf, size_t len) -+{ -+ return netdev_store(dev, attr, buf, len, modify_napi_threaded); -+} -+static DEVICE_ATTR_RW(threaded); -+ - static struct attribute *net_class_attrs[] __ro_after_init = { - &dev_attr_netdev_group.attr, - &dev_attr_type.attr, -@@ -587,6 +626,7 @@ static struct attribute *net_class_attrs - &dev_attr_proto_down.attr, - &dev_attr_carrier_up_count.attr, - &dev_attr_carrier_down_count.attr, -+ &dev_attr_threaded.attr, - NULL, - }; - ATTRIBUTE_GROUPS(net_class); |