net: drop_monitor: make last_rx timestamp private
It was recently pointed out to me that the last_rx field of the net_device structure wasn't updated regularly. In fact only the bonding driver really uses it currently. Since the drop_monitor code relies on the last_rx field to detect drops on recevie in hardware, We need to find a more reliable way to rate limit our drop checks (so that we don't check for drops on every frame recevied, which would be inefficient. This patch makes a last_rx timestamp that is private to the drop monitor code and is updated for every device that we track. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
3f968de276
commit
5848cc096a
|
@ -52,6 +52,7 @@ struct per_cpu_dm_data {
|
|||
|
||||
struct dm_hw_stat_delta {
|
||||
struct net_device *dev;
|
||||
unsigned long last_rx;
|
||||
struct list_head list;
|
||||
struct rcu_head rcu;
|
||||
unsigned long last_drop_val;
|
||||
|
@ -180,18 +181,25 @@ static void trace_napi_poll_hit(struct napi_struct *napi)
|
|||
struct dm_hw_stat_delta *new_stat;
|
||||
|
||||
/*
|
||||
* Ratelimit our check time to dm_hw_check_delta jiffies
|
||||
* Don't check napi structures with no associated device
|
||||
*/
|
||||
if (!napi->dev ||
|
||||
!time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
|
||||
if (!napi->dev)
|
||||
return;
|
||||
|
||||
rcu_read_lock();
|
||||
list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
|
||||
/*
|
||||
* only add a note to our monitor buffer if:
|
||||
* 1) this is the dev we received on
|
||||
* 2) its after the last_rx delta
|
||||
* 3) our rx_dropped count has gone up
|
||||
*/
|
||||
if ((new_stat->dev == napi->dev) &&
|
||||
(time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) &&
|
||||
(napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
|
||||
trace_drop_common(NULL, NULL);
|
||||
new_stat->last_drop_val = napi->dev->stats.rx_dropped;
|
||||
new_stat->last_rx = jiffies;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
@ -287,6 +295,7 @@ static int dropmon_net_event(struct notifier_block *ev_block,
|
|||
goto out;
|
||||
|
||||
new_stat->dev = dev;
|
||||
new_stat->last_rx = jiffies;
|
||||
INIT_RCU_HEAD(&new_stat->rcu);
|
||||
spin_lock(&trace_state_lock);
|
||||
list_add_rcu(&new_stat->list, &hw_stats_list);
|
||||
|
|
Loading…
Reference in a new issue