From bfe459fb42007f41d7c26efc6fec349a0e4e5f0b Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 20 Feb 2012 20:12:04 -0500
Subject: [PATCH] Add freebsd support for getcpu (use cpu nr 0)

commit 08bf1cc1c8731a717e253932f3e36672b0476078 upstream.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Christian Babeux <christian.babeux@efficios.com>
---
 liblttng-ust/compat.h  | 22 ----------------------
 libringbuffer/getcpu.h | 42 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/liblttng-ust/compat.h b/liblttng-ust/compat.h
index 803cc12d..2690a760 100644
--- a/liblttng-ust/compat.h
+++ b/liblttng-ust/compat.h
@@ -19,28 +19,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-/*
- * sched_getcpu.
- */
-#ifdef __linux__
-
-#ifdef __UCLIBC__
-#include <sys/syscall.h>
-#define __getcpu(cpu, node, cache)	syscall(__NR_getcpu, cpu, node, cache)
-static inline
-int sched_getcpu(void)
-{
-	int c, s;
-
-	s = __getcpu(&c, NULL, NULL);
-	return (s == -1) ? s : c;
-}
-#endif	/* __UCLIBC__ */
-
-#else
-#error "Please add support for your OS into liblttng-ust/compat.h."
-#endif
-
 /*
  * lttng_ust_getprocname.
  */
diff --git a/libringbuffer/getcpu.h b/libringbuffer/getcpu.h
index 44d0d559..0a619417 100644
--- a/libringbuffer/getcpu.h
+++ b/libringbuffer/getcpu.h
@@ -20,7 +20,6 @@
  */
 
 #include <urcu/compiler.h>
-#include <sched.h>
 
 #ifdef LTTNG_UST_DEBUG_VALGRIND
 
@@ -37,6 +36,30 @@ int lttng_ust_get_cpu(void)
 
 #else
 
+/*
+ * sched_getcpu.
+ */
+#ifdef __linux__
+
+#ifdef __UCLIBC__
+#include <sys/syscall.h>
+#define __getcpu(cpu, node, cache)	syscall(__NR_getcpu, cpu, node, cache)
+/*
+ * If getcpu is not implemented in the kernel, use cpu 0 as fallback.
+ */
+static inline
+int lttng_ust_get_cpu(void)
+{
+	int cpu, ret;
+
+	ret = __getcpu(&cpu, NULL, NULL);
+	if (caa_unlikely(ret < 0))
+		return 0;
+	return c;
+}
+#else /* __UCLIBC__ */
+#include <sched.h>
+
 /*
  * If getcpu is not implemented in the kernel, use cpu 0 as fallback.
  */
@@ -50,6 +73,23 @@ int lttng_ust_get_cpu(void)
 		return 0;
 	return cpu;
 }
+#endif	/* __UCLIBC__ */
+
+#elif defined(__FreeBSD__)
+
+/*
+ * FreeBSD does not allow query of CPU ID. Always use CPU number 0, with
+ * the assocated performance degradation on SMP.
+ */
+static inline
+int lttng_ust_get_cpu(void)
+{
+	return 0;
+}
+
+#else
+#error "Please add support for your OS into liblttng-ust/compat.h."
+#endif
 
 #endif
 
-- 
2.34.1