| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20081203160134.GA6549@hmsreliant.think-freely.org>
Date: Wed, 3 Dec 2008 11:01:34 -0500
From: Neil Horman <nhorman@...driver.com>
To: Mathieu Desnoyers <compudj@...stal.dyndns.org>
Cc: ltt-dev@...ts.casi.polymtl.ca, linux-kernel@...r.kernel.org
Subject: Re: [ltt-dev] [PATCH] add tracepoints to track change in napi
states on network receive
On Tue, Dec 02, 2008 at 03:01:50PM -0500, Mathieu Desnoyers wrote:
> * Neil Horman (nhorman@...driver.com) wrote:
> > Hey there-
> > I thought it would be handy to track the napi receive state of different
> > network devices using ltt. This patch adds trace points to indicate when a napi
> > instance has been scheduled, when its serviced and when it completes.
> >
>
> Sounds great, see comments below,
<snip>
Hey,
New patch, with previous comments taken into account.
Patch to track the napi receive stat of different network devices using ltt.
Adds trace points to indicate when a napi instance has been scheduled, when its
serviced and when it completes
Regards
Neil
Signed-off-by: Neil Horman <nhorman@...driver.com>
include/linux/netdevice.h | 5 +++++
include/trace/netdevice.h | 30 ++++++++++++++++++++++++++++++
ltt/probes/net-trace.c | 22 ++++++++++++++++++++++
net/core/dev.c | 7 ++++++-
4 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 488c56e..7da71eb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -43,6 +43,9 @@
#include <net/net_namespace.h>
+struct napi_struct;
+#include <trace/netdevice.h>
+
struct vlan_group;
struct ethtool_ops;
struct netpoll_info;
@@ -386,6 +389,7 @@ static inline void napi_complete(struct napi_struct *n)
local_irq_save(flags);
__napi_complete(n);
local_irq_restore(flags);
+ trace_napi_complete(n);
}
/**
@@ -1726,6 +1730,7 @@ static inline int skb_bond_should_drop(struct sk_buff *skb)
return 0;
}
+
#endif /* __KERNEL__ */
#endif /* _LINUX_DEV_H */
diff --git a/include/trace/netdevice.h b/include/trace/netdevice.h
new file mode 100644
index 0000000..ba48f6c
--- /dev/null
+++ b/include/trace/netdevice.h
@@ -0,0 +1,30 @@
+#ifndef _INCLUDE_NETDEVICE_H_
+#define _INCLUDE_NETDEVICE_H_
+
+#include <linux/netdevice.h>
+
+/* Tracepoints */
+
+/*
+ * Note these first 2 traces are actually in __napi_schedule and net_rx_action
+ * respectively. The former is in __napi_schedule because it uses at-most-once
+ * logic and placing it in the calling routine (napi_schedule) would produce
+ * countless trace events that were effectively no-ops. napi_poll is
+ * implemented in net_rx_action, because thats where we do our polling on
+ * devices. The last trace point is in napi_complete, right where you would
+ * think it would be.
+ */
+DEFINE_TRACE(napi_schedule,
+ TPPROTO(struct napi_struct *n),
+ TPARGS(n));
+
+DEFINE_TRACE(napi_poll,
+ TPPROTO(struct napi_struct *n),
+ TPARGS(n));
+
+DEFINE_TRACE(napi_complete,
+ TPPROTO(struct napi_struct *n),
+ TPARGS(n));
+
+#endif
+
diff --git a/ltt/probes/net-trace.c b/ltt/probes/net-trace.c
index bac2b21..bd4e621 100644
--- a/ltt/probes/net-trace.c
+++ b/ltt/probes/net-trace.c
@@ -9,6 +9,7 @@
#include <trace/ipv4.h>
#include <trace/ipv6.h>
#include <trace/socket.h>
+#include <trace/netdevice.h>
void probe_net_dev_xmit(struct sk_buff *skb)
{
@@ -104,6 +105,27 @@ void probe_socket_call(int call, unsigned long a0)
"call %d a0 %lu", call, a0);
}
+void probe_napi_schedule(struct napi_struct *n)
+{
+ trace_mark_tp(net_napi_schedule, napi_schedule, probe_napi_schedule,
+ "schedule napi_struct %p name %s",
+ n, n->dev->name);
+}
+
+void probe_napi_poll(struct napi_struct *n)
+{
+ trace_mark_tp(net_napi_poll, napi_poll, probe_napi_poll,
+ "service napi_struct %p name %s",
+ n, n->dev->name);
+}
+
+void probe_napi_complete(struct napi_struct *n)
+{
+ trace_mark_tp(net_napi_complete, napi_complete, probe_napi_complete,
+ "complete napi_struct %p name %s",
+ n, n->dev->name);
+}
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Net Tracepoint Probes");
diff --git a/net/core/dev.c b/net/core/dev.c
index 836fe6e..0c55c0f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -128,6 +128,7 @@
#include <linux/jhash.h>
#include <linux/random.h>
#include <trace/net.h>
+#include <trace/netdevice.h>
#include "net-sysfs.h"
@@ -2329,6 +2330,8 @@ void __napi_schedule(struct napi_struct *n)
{
unsigned long flags;
+ trace_napi_poll(n);
+
local_irq_save(flags);
list_add_tail(&n->poll_list, &__get_cpu_var(softnet_data).poll_list);
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
@@ -2380,8 +2383,10 @@ static void net_rx_action(struct softirq_action *h)
* accidently calling ->poll() when NAPI is not scheduled.
*/
work = 0;
- if (test_bit(NAPI_STATE_SCHED, &n->state))
+ if (test_bit(NAPI_STATE_SCHED, &n->state)) {
+ trace_napi_poll(n);
work = n->poll(n, weight);
+ }
WARN_ON_ONCE(work > weight);
--
/****************************************************
* Neil Horman <nhorman@...driver.com>
* Software Engineer, Red Hat
****************************************************/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists