Re: [RFC PATCH v4 4/5] skb: add tracepoints to freeing skb
From: Neil Horman <nhorman@tuxdriver.com>
Date: 2010-08-27 12:38:57
Also in:
lkml
On Wed, Jul 28, 2010 at 03:33:57PM +0900, Koki Sanagi wrote:
CHANGE-LOG since v3:
-remove tracepoint of dev_kfree_skb_irq and skb_free_datagram_locked.
Insead of them, add trace_kfree_skb before __kfree_skb in net_tx_action and
skb_free_datagram_locked. And there is no change of about the location of
trace_consume_skb to keep a symmetry against trace_kfree_skb.
This patch adds tracepoint to consume_skb and add trace_kfree_skb before
__kfree_skb in skb_free_datagram_locked and net_tx_action.
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.
sshd-6828 [000] 112689.258154: consume_skb: skbaddr=f2d99bb8
Signed-off-by: Koki Sanagi <redacted>Acked-by: Neil Horman <nhorman@tuxdriver.com>
quoted hunk ↗ jump to hunk
--- include/trace/events/skb.h | 17 +++++++++++++++++ net/core/datagram.c | 1 + net/core/dev.c | 2 ++ net/core/skbuff.c | 1 + 4 files changed, 21 insertions(+), 0 deletions(-)diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 4b2be6d..75ce9d5 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h@@ -35,6 +35,23 @@ 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(skb_copy_datagram_iovec, TP_PROTO(const struct sk_buff *skb, int len),diff --git a/net/core/datagram.c b/net/core/datagram.c index 251997a..282806b 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c@@ -243,6 +243,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) unlock_sock_fast(sk, slow); /* skb is now orphaned, can be freed outside of locked section */ + trace_kfree_skb(skb, skb_free_datagram_locked); __kfree_skb(skb); } EXPORT_SYMBOL(skb_free_datagram_locked);diff --git a/net/core/dev.c b/net/core/dev.c index 9ea9c1e..92d79bf 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"@@ -2577,6 +2578,7 @@ static void net_tx_action(struct softirq_action *h) clist = clist->next; WARN_ON(atomic_read(&skb->users)); + trace_kfree_skb(skb, net_tx_action); __kfree_skb(skb); } }diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 7da58a2..9cb91a5 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); --To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html