lkml.org 
[lkml]   [2010]   [Jun]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v2 4/5] skb: add tracepoints to freeing skb
(2010/06/25 13:55), Eric Dumazet wrote:
> Le vendredi 25 juin 2010 à 09:59 +0900, Koki Sanagi a écrit :
>> This patch adds tracepoint to consume_skb and dev_kfree_skb_irq.
>> Combinating with tracepoint on dev_hard_start_xmit, we can check how long it
>> takes to free transmited packets. And using it, we can calculate how many
>> packets driver had at that time. It is useful when a drop of transmited packet
>> is a problem.
>>
>> <idle>-0 [001] 241409.218333: consume_skb: skbaddr=dd6b2fb8
>> <idle>-0 [001] 241409.490555: dev_kfree_skb_irq: skbaddr=f5e29840
>>
>> Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
>> ---
>> include/trace/events/skb.h | 36 ++++++++++++++++++++++++++++++++++++
>> net/core/dev.c | 2 ++
>> net/core/skbuff.c | 1 +
>> 3 files changed, 39 insertions(+), 0 deletions(-)
>>
>> diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
>> index 4b2be6d..6ab5b34 100644
>> --- a/include/trace/events/skb.h
>> +++ b/include/trace/events/skb.h
>> @@ -35,6 +35,42 @@ TRACE_EVENT(kfree_skb,
>> __entry->skbaddr, __entry->protocol, __entry->location)
>> );
>>
>> +TRACE_EVENT(consume_skb,
>> +
>> + TP_PROTO(struct sk_buff *skb),
>> +
>> + TP_ARGS(skb),
>> +
>> + TP_STRUCT__entry(
>> + __field( void *, skbaddr )
>> + ),
>> +
>> + TP_fast_assign(
>> + __entry->skbaddr = skb;
>> + ),
>> +
>> + TP_printk("skbaddr=%p",
>> + __entry->skbaddr)
>> +);
>> +
>> +TRACE_EVENT(dev_kfree_skb_irq,
>> +
>> + TP_PROTO(struct sk_buff *skb),
>> +
>> + TP_ARGS(skb),
>> +
>> + TP_STRUCT__entry(
>> + __field( void *, skbaddr )
>> + ),
>> +
>> + TP_fast_assign(
>> + __entry->skbaddr = skb;
>> + ),
>> +
>> + TP_printk("skbaddr=%p",
>> + __entry->skbaddr)
>> +);
>> +
>> TRACE_EVENT(skb_copy_datagram_iovec,
>>
>> TP_PROTO(const struct sk_buff *skb, int len),
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index 4b64b21..807b1ca 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -131,6 +131,7 @@
>> #include <linux/random.h>
>> #include <trace/events/napi.h>
>> #include <trace/events/net.h>
>> +#include <trace/events/skb.h>
>> #include <linux/pci.h>
>>
>> #include "net-sysfs.h"
>> @@ -1580,6 +1581,7 @@ void dev_kfree_skb_irq(struct sk_buff *skb)
>> struct softnet_data *sd;
>> unsigned long flags;
>>
>> + trace_dev_kfree_skb_irq(skb);
>> local_irq_save(flags);
>> sd = &__get_cpu_var(softnet_data);
>> skb->next = sd->completion_queue;
>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>> index 34432b4..a7b4036 100644
>> --- a/net/core/skbuff.c
>> +++ b/net/core/skbuff.c
>> @@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb)
>> smp_rmb();
>> else if (likely(!atomic_dec_and_test(&skb->users)))
>> return;
>> + trace_consume_skb(skb);
>> __kfree_skb(skb);
>> }
>> EXPORT_SYMBOL(consume_skb);
>>
>
>
> You might add a trace point to skb_free_datagram_locked() too, since it
> contains an inlined consume_skb()
>

I think it is contrary.
skb_free_datagram_locked() contains consume_skb(), so tracepoint isn't needed.
Because skb_free_datagram_locked() can be traced by trace_consume_skb().



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-06-25 09:15    [W:0.090 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site