From 3f969213cb1f77a80237f0ba914f73b9ccf2fafb Mon Sep 17 00:00:00 2001
From: k-nakahara <k-nakahara@iij.ad.jp>
Date: Mon, 4 Apr 2016 13:01:33 +0900
Subject: [PATCH 2/3] add dtrace probe

---
 sys/kern/uipc_mbuf.c  | 2 ++
 sys/kern/uipc_mbuf2.c | 9 ++++++++-
 sys/sys/mbuf.h        | 4 ++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index 4049b2b..23f2a5d 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -87,6 +87,8 @@ __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.163 2015/08/24 22:21:26 pooka Exp $"
 
 #include <net/if.h>
 
+SDT_PROVIDER_DEFINE(mbuf);
+
 pool_cache_t mb_cache;	/* mbuf cache */
 pool_cache_t mcl_cache;	/* mbuf cluster cache */
 pool_cache_t mtag_cache;/* m_tag cache */
diff --git a/sys/kern/uipc_mbuf2.c b/sys/kern/uipc_mbuf2.c
index 18a6c97..6b2707d 100644
--- a/sys/kern/uipc_mbuf2.c
+++ b/sys/kern/uipc_mbuf2.c
@@ -70,6 +70,9 @@ __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf2.c,v 1.30 2013/10/08 19:59:49 christos Exp
 #include <sys/mbuf.h>
 #include <sys/pool.h>
 
+SDT_PROBE_DEFINE2(mbuf, m_tag, pool_cache_get, success, "int", "int");
+SDT_PROBE_DEFINE2(mbuf, m_tag, pool_cache_get, fail, "int", "int");
+
 /*
  * ensure that [off, off + len) is contiguous on the mbuf chain "m".
  * packet chain before "off" is kept untouched.
@@ -264,8 +267,12 @@ m_tag_get(int type, int len, int wait)
 
 	tp = pool_cache_get(mtag_cache,
 	    wait == M_NOWAIT ? PR_NOWAIT : PR_WAITOK);
-	if (tp == NULL)
+	if (tp == NULL) {
+		SDT_PROBE2(mbuf, m_tag, pool_cache_get, fail, type, len);
 		return NULL;
+	} else {
+		SDT_PROBE2(mbuf, m_tag, pool_cache_get, success, type, len);
+	}
 	t = &tp->mp_tag;
 	t->m_tag_id = type;
 	t->m_tag_len = len;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index c3da181..398eafb 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -66,6 +66,7 @@
 
 #ifdef _KERNEL_OPT
 #include "opt_mbuftrace.h"
+#include "opt_dtrace.h"
 #endif
 
 #ifndef M_WAITOK
@@ -76,6 +77,7 @@
 #if defined(_KERNEL)
 #include <sys/percpu_types.h>
 #endif /* defined(_KERNEL) */
+#include <sys/sdt.h>
 
 /* For offsetof() */
 #if defined(_KERNEL) || defined(_STANDALONE)
@@ -86,6 +88,8 @@
 
 #include <uvm/uvm_param.h>	/* for MIN_PAGE_SIZE */
 
+SDT_PROVIDER_DECLARE(mbuf);
+
 /*
  * Mbufs are of a single size, MSIZE (machine/param.h), which
  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
-- 
2.1.0