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| author | Neil Horman <nhorman@tuxdriver.com> | 2009-09-02 14:37:45 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-09-02 14:37:45 -0700 |
| commit | 5848cc096a23b80b3d15c27d72299f79caf7c517 (patch) | |
| tree | f43257578c3e5fc248903544c430294d914287a7 /net/core | |
| parent | 3f968de276a8e585deb182d4ba56013a479c80bc (diff) | |
| download | linux-5848cc096a23b80b3d15c27d72299f79caf7c517.tar.gz linux-5848cc096a23b80b3d15c27d72299f79caf7c517.tar.bz2 linux-5848cc096a23b80b3d15c27d72299f79caf7c517.zip | |
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>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/drop_monitor.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index d31120248c03..0a113f26bc9f 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -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); |