[PATCH] drop_monitor: allow more events per second

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From: Eric Dumazet <edumazet@xxxxxxxxxx>

It seems there is a logic error in trace_drop_common(), since we store
only 64 drops, even if they are from same location.

This fix is a one liner, but we probably need more work to avoid useless
atomic dec/inc

Now I can watch 1 Mpps drops through dropwatch...

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxxxxx>
---
Neil, it seems this code is not SMP/preempt safe. Worker can free our
data under us, and genlmsg_new() can return NULL under stress.

 net/core/drop_monitor.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 7f36b38..5c3c81a 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -150,6 +150,7 @@ static void trace_drop_common(struct sk_buff *skb, void *location)
 	for (i = 0; i < msg->entries; i++) {
 		if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
 			msg->points[i].count++;
+			atomic_inc(&data->dm_hit_count);
 			goto out;
 		}
 	}


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Linux Kernel Discussion]     [Ethernet Bridging]     [Linux Wireless Networking]     [Linux Bluetooth Networking]     [Linux Networking Users]     [VLAN]     [Git]     [IETF Annouce]     [Linux Assembly]     [Security]     [Bugtraq]     [Photo]     [Singles Social Networking]     [Yosemite Information]     [MIPS Linux]     [ARM Linux Kernel]     [ARM Linux]     [Linux Virtualization]     [Linux Security]     [Linux IDE]     [Linux RAID]     [Linux SCSI]     [Free Dating]

Add to Google Powered by Linux