@@ -1490,17 +1490,24 @@ EXPORT_SYMBOL(netdev_notify_peers);
static int napi_threaded_poll(void *data);
-static void napi_thread_start(struct napi_struct *n)
+static int napi_kthread_create(struct napi_struct *n)
{
- if (test_bit(NAPI_STATE_THREADED, &n->state) && !n->thread)
- n->thread = kthread_create(napi_threaded_poll, n, "%s-%d",
- n->dev->name, n->napi_id);
+ int err = 0;
+
+ n->thread = kthread_create(napi_threaded_poll, n, "napi/%s-%d",
+ n->dev->name, n->napi_id);
+ if (IS_ERR(n->thread)) {
+ err = PTR_ERR(n->thread);
+ pr_err("kthread_create failed with err %d\n", err);
+ n->thread = NULL;
+ }
+
+ return err;
}
static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
- struct napi_struct *n;
int ret;
ASSERT_RTNL();
@@ -1532,9 +1539,6 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
if (!ret && ops->ndo_open)
ret = ops->ndo_open(dev);
- list_for_each_entry(n, &dev->napi_list, dev_list)
- napi_thread_start(n);
-
netpoll_poll_enable(dev);
if (ret)
@@ -1585,6 +1589,7 @@ static void napi_thread_stop(struct napi_struct *n)
if (!n->thread)
return;
kthread_stop(n->thread);
+ clear_bit(NAPI_STATE_THREADED, &n->state);
n->thread = NULL;
}
@@ -4267,7 +4272,7 @@ int gro_normal_batch __read_mostly = 8;
static inline void ____napi_schedule(struct softnet_data *sd,
struct napi_struct *napi)
{
- if (napi->thread) {
+ if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
wake_up_process(napi->thread);
return;
}
@@ -6687,25 +6692,25 @@ static void init_gro_hash(struct napi_struct *napi)
int napi_set_threaded(struct napi_struct *n, bool threaded)
{
- ASSERT_RTNL();
+ int err = 0;
- if (n->dev->flags & IFF_UP)
- return -EBUSY;
+ ASSERT_RTNL();
if (threaded == !!test_bit(NAPI_STATE_THREADED, &n->state))
return 0;
- if (threaded)
+ if (threaded) {
+ if (!n->thread) {
+ err = napi_kthread_create(n);
+ if (err)
+ goto out;
+ }
set_bit(NAPI_STATE_THREADED, &n->state);
- else
+ } else {
clear_bit(NAPI_STATE_THREADED, &n->state);
+ }
- /* if the device is initializing, nothing todo */
- if (test_bit(__LINK_STATE_START, &n->dev->state))
- return 0;
-
- napi_thread_stop(n);
- napi_thread_start(n);
- return 0;
+out:
+ return err;
}
EXPORT_SYMBOL(napi_set_threaded);
@@ -6750,6 +6755,7 @@ void napi_disable(struct napi_struct *n)
msleep(1);
hrtimer_cancel(&n->timer);
+ napi_thread_stop(n);
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
@@ -6870,6 +6876,7 @@ static int napi_thread_wait(struct napi_struct *napi)
while (!kthread_should_stop() && !napi_disable_pending(napi)) {
if (test_bit(NAPI_STATE_SCHED, &napi->state)) {
+ WARN_ON(!list_empty(&napi->poll_list));
__set_current_state(TASK_RUNNING);
return 0;
}
@@ -609,11 +609,6 @@ static ssize_t threaded_store(struct device *dev,
goto unlock;
}
- if (netdev->flags & IFF_UP) {
- ret = -EBUSY;
- goto unlock;
- }
-
bmap = __alloc_thread_bitmap(netdev, &bits);
if (!bmap) {
ret = -ENOMEM;
@@ -626,7 +621,9 @@ static ssize_t threaded_store(struct device *dev,
i = 0;
list_for_each_entry(n, &netdev->napi_list, dev_list) {
- napi_set_threaded(n, test_bit(i, bmap));
+ ret = napi_set_threaded(n, test_bit(i, bmap));
+ if (ret)
+ goto free_unlock;
i++;
}
ret = len;
This commit mainly addresses the threaded config to make the switch between softirq based and kthread based NAPI processing not require a device down/up. It also moves the kthread_create() call to the sysfs handler when user tries to enable "threaded" on napi, and properly handles the kthread_create() failure. This is because certain drivers do not have the napi created and linked to the dev when dev_open() is called. So the previous implementation does not work properly there. Signed-off-by: Wei Wang <weiwan@google.com> --- Changes since RFC: changed the thread name to napi/<dev>-<napi-id> net/core/dev.c | 49 +++++++++++++++++++++++++------------------- net/core/net-sysfs.c | 9 +++----- 2 files changed, 31 insertions(+), 27 deletions(-)