Messages in this thread Patch in this message | | | Date | Wed, 3 Dec 2008 12:45:00 -0500 | From | Neil Horman <> | Subject | Re: [ltt-dev] [PATCH] add tracepoints to track change in napi states on network receive |
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On Wed, Dec 03, 2008 at 12:25:07PM -0500, Mathieu Desnoyers wrote: > Almost there :) > > There is a extra whitespace above, > > and also "schedule napi_struct" should probably be changed into > napi_struct only, this removes the whitespace and duplicated information > (I guess we know that given we are in event net_napi_schedule, this will > have something to do with schedule...). Same applies to trace_mark_tp > below. > > Thanks, > > Mathieu
Sure, here you go, new patch
Patch to trace napi states for various net devices and their napi instances. Traces scheduling, servicing and completion of a napi poll request.
Regards Neil
Signed-off-by: Neil Horman <nhorman@tuxdriver.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..e887e70 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, + "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, + "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, + "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@tuxdriver.com> * Software Engineer, Red Hat ****************************************************/
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