From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752604AbYLBUCB (ORCPT ); Tue, 2 Dec 2008 15:02:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750920AbYLBUBx (ORCPT ); Tue, 2 Dec 2008 15:01:53 -0500 Received: from tomts20-srv.bellnexxia.net ([209.226.175.74]:39450 "EHLO tomts20-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843AbYLBUBw (ORCPT ); Tue, 2 Dec 2008 15:01:52 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AswEAJQeNUlMROB9/2dsb2JhbACBbdEdgXeBCA Date: Tue, 2 Dec 2008 15:01:50 -0500 From: Mathieu Desnoyers To: Neil Horman Cc: ltt-dev@lists.casi.polymtl.ca, linux-kernel@vger.kernel.org Subject: Re: [ltt-dev] [PATCH] add tracepoints to track change in napi states on network receive Message-ID: <20081202200150.GA27282@Krystal> References: <20081202195129.GA30042@hmsreliant.think-freely.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20081202195129.GA30042@hmsreliant.think-freely.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 14:56:11 up 15 days, 20:36, 2 users, load average: 0.35, 0.68, 0.82 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Neil Horman (nhorman@tuxdriver.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, > Regards > Neil > > Signed-off-by: Neil Horman > > > include/linux/netdevice.h | 4 ++++ > include/trace/netdevice.h | 36 ++++++++++++++++++++++++++++++++++++ > ltt/probes/net-trace.c | 22 ++++++++++++++++++++++ > net/core/dev.c | 6 +++++- > 4 files changed, 67 insertions(+), 1 deletion(-) > > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 488c56e..9f35f84 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -43,6 +43,8 @@ > > #include > > +#include > + > struct vlan_group; > struct ethtool_ops; > struct netpoll_info; > @@ -386,6 +388,7 @@ 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 +1729,7 @@ 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..c75030b > --- /dev/null > +++ b/include/trace/netdevice.h > @@ -0,0 +1,36 @@ > +#ifndef _INCLUDE_NETDEVICE_H_ > +#define _INCLUDE_NETDEVICE_H_ > + > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > +#include > + > +#include > + Hrm ? Do we need all these includes ? > +/* Tracepoints */ > + > +/* > + * Note this is actually the trace for __netif_rx_schedule > + * since I wanted to trace every call which had us set the RX_SCHED bit Could you put this comment in the 3rd person ? Also, I wonder if that mean there might be other cause for schedule we would not trace ? > + */ > +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..3de1ff8 100644 > --- a/ltt/probes/net-trace.c > +++ b/ltt/probes/net-trace.c > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > > 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 instance %p, dev %s", Field names should have no space, e.g. : "napi_struct %p name %s" Mathieu > + 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 instance %p, dev %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 instance %p, dev %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..6021010 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -2329,6 +2329,8 @@ 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 +2382,10 @@ 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 > * Software Engineer, Red Hat > ****************************************************/ > > _______________________________________________ > ltt-dev mailing list > ltt-dev@lists.casi.polymtl.ca > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68