dropmon: add ability to detect when hardware dropsrxpackets
Patch to add the ability to detect drops in hardware interfaces via dropwatch.
Adds a tracepoint to net_rx_action to signal everytime a napi instance is
polled. The dropmon code then periodically checks to see if the rx_frames
counter has changed, and if so, adds a drop notification to the netlink
protocol, using the reserved all-0's vector to indicate the drop location was in
hardware, rather than somewhere in the code.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
include/linux/net_dropmon.h | 8 ++
include/trace/napi.h | 11 +++
net/core/dev.c | 5 +
net/core/drop_monitor.c | 124 ++++++++++++++++++++++++++++++++++++++++++--
net/core/net-traces.c | 4 +
net/core/netpoll.c | 2
6 files changed, 149 insertions(+), 5 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 64f51ee..00b14e2 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -24,6 +24,7 @@
#include <net/tcp.h>
#include <net/udp.h>
#include <asm/unaligned.h>
+#include <trace/napi.h>
/*
* We maintain a small pool of fully-sized skbs, to make sure the
@@ -137,6 +138,7 @@
set_bit(NAPI_STATE_NPSVC, &napi->state);
work = napi->poll(napi, budget);
+ trace_napi_poll(napi->dev);
clear_bit(NAPI_STATE_NPSVC, &napi->state);
atomic_dec(&trapped);