diff mbox series

[net-next,09/10] drop_monitor: Make drop queue length configurable

Message ID 20190807103059.15270-10-idosch@idosch.org
State Changes Requested
Delegated to: David Miller
Headers show
Series drop_monitor: Capture dropped packets and metadata | expand

Commit Message

Ido Schimmel Aug. 7, 2019, 10:30 a.m. UTC 
From: Ido Schimmel <idosch@mellanox.com>

In packet alert mode, each CPU holds a list of dropped skbs that need to
be processed in process context and sent to user space. To avoid
exhausting the system's memory the maximum length of this queue is
currently set to 1000.

Allow users to tune the length of this queue according to their needs.
The configured length is reported to user space when drop monitor
configuration is queried.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
 include/uapi/linux/net_dropmon.h |  1 +
 net/core/drop_monitor.c          | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_dropmon.h
index 7b15f632c045..8658bcd07e0e 100644
--- a/include/uapi/linux/net_dropmon.h
+++ b/include/uapi/linux/net_dropmon.h
@@ -78,6 +78,7 @@  enum net_dm_attr {
 	NET_DM_ATTR_PAD,
 	NET_DM_ATTR_TRUNC_LEN,			/* u32 */
 	NET_DM_ATTR_ORIG_LEN,			/* u32 */
+	NET_DM_ATTR_QUEUE_LEN,			/* u32 */
 
 	__NET_DM_ATTR_MAX,
 	NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index f5dfad283fe2..c9b68a093e0f 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -78,6 +78,7 @@  static LIST_HEAD(hw_stats_list);
 
 static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
 static u32 net_dm_trunc_len;
+static u32 net_dm_queue_len = 1000;
 
 struct net_dm_alert_ops {
 	void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
@@ -93,8 +94,6 @@  struct net_dm_skb_cb {
 
 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
 
-#define NET_DM_QUEUE_LEN 1000
-
 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
 {
 	size_t al;
@@ -289,7 +288,7 @@  static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
 	data = this_cpu_ptr(&dm_cpu_data);
 
 	spin_lock_irqsave(&data->drop_queue.lock, flags);
-	if (skb_queue_len(&data->drop_queue) < NET_DM_QUEUE_LEN)
+	if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
 		__skb_queue_tail(&data->drop_queue, nskb);
 	else
 		goto unlock_free;
@@ -638,6 +637,14 @@  static void net_dm_trunc_len_set(struct genl_info *info)
 	net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
 }
 
+static void net_dm_queue_len_set(struct genl_info *info)
+{
+	if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
+		return;
+
+	net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
+}
+
 static int net_dm_cmd_config(struct sk_buff *skb,
 			struct genl_info *info)
 {
@@ -655,6 +662,8 @@  static int net_dm_cmd_config(struct sk_buff *skb,
 
 	net_dm_trunc_len_set(info);
 
+	net_dm_queue_len_set(info);
+
 	return 0;
 }
 
@@ -686,6 +695,9 @@  static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
 	if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
 		goto nla_put_failure;
 
+	if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
+		goto nla_put_failure;
+
 	genlmsg_end(msg, hdr);
 
 	return 0;
@@ -758,6 +770,7 @@  static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
 	[NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
 	[NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
 	[NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
+	[NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
 };
 
 static const struct genl_ops dropmon_ops[] = {