While reading weight_p, it can be changed concurrently. Thus, we need
to add READ_ONCE() to its reader.
Also, dev_[rt]x_weight can be read/written at the same time. So, we
need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to
use the same weight_p while changing dev_[rt]x_weight, we add a mutex
in proc_do_dev_weight().
Fixes:
3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality")
Fixes:
1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net_rps_action_and_irq_enable(sd);
}
net_rps_action_and_irq_enable(sd);
}
- napi->weight = dev_rx_weight;
+ napi->weight = READ_ONCE(dev_rx_weight);
while (again) {
struct sk_buff *skb;
while (again) {
struct sk_buff *skb;
static int proc_do_dev_weight(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
static int proc_do_dev_weight(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
+ static DEFINE_MUTEX(dev_weight_mutex);
+ int ret, weight;
+ mutex_lock(&dev_weight_mutex);
ret = proc_dointvec(table, write, buffer, lenp, ppos);
ret = proc_dointvec(table, write, buffer, lenp, ppos);
- if (ret != 0)
- return ret;
-
- dev_rx_weight = weight_p * dev_weight_rx_bias;
- dev_tx_weight = weight_p * dev_weight_tx_bias;
+ if (!ret && write) {
+ weight = READ_ONCE(weight_p);
+ WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias);
+ WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias);
+ }
+ mutex_unlock(&dev_weight_mutex);
void __qdisc_run(struct Qdisc *q)
{
void __qdisc_run(struct Qdisc *q)
{
- int quota = dev_tx_weight;
+ int quota = READ_ONCE(dev_tx_weight);
int packets;
while (qdisc_restart(q, &packets)) {
int packets;
while (qdisc_restart(q, &packets)) {