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authorPaolo Abeni2020-09-18 18:00:46 +0200
committerDavid S. Miller2020-09-21 13:56:37 -0700
commit7d58e6555870d01d85b181ba2a16b217a1ea8bdd (patch)
tree253a8bbcae758058ac2bbc359b45592c225a5243 /net
parentc4f084edd358e54a89c0c562b9c7c50994caffe0 (diff)
net-sysfs: add backlog len and CPU id to softnet data
Currently the backlog status in not exposed to user-space. Since long backlogs (or simply not empty ones) can be a source of noticeable latency, -RT deployments need some way to inspect it. Additionally, there isn't a direct match between 'softnet_stat' lines and the related CPU - sd for offline CPUs are not dumped - so this patch also includes the CPU id into such entry. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/net-procfs.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
index 6bbd06f7dc7d..c714e6a9dad4 100644
--- a/net/core/net-procfs.c
+++ b/net/core/net-procfs.c
@@ -116,6 +116,12 @@ static int dev_seq_show(struct seq_file *seq, void *v)
return 0;
}
+static u32 softnet_backlog_len(struct softnet_data *sd)
+{
+ return skb_queue_len_lockless(&sd->input_pkt_queue) +
+ skb_queue_len_lockless(&sd->process_queue);
+}
+
static struct softnet_data *softnet_get_online(loff_t *pos)
{
struct softnet_data *sd = NULL;
@@ -159,12 +165,17 @@ static int softnet_seq_show(struct seq_file *seq, void *v)
rcu_read_unlock();
#endif
+ /* the index is the CPU id owing this sd. Since offline CPUs are not
+ * displayed, it would be othrwise not trivial for the user-space
+ * mapping the data a specific CPU
+ */
seq_printf(seq,
- "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
+ "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
sd->processed, sd->dropped, sd->time_squeeze, 0,
0, 0, 0, 0, /* was fastroute */
0, /* was cpu_collision */
- sd->received_rps, flow_limit_count);
+ sd->received_rps, flow_limit_count,
+ softnet_backlog_len(sd), (int)seq->index);
return 0;
}