[Midnightbsd-cvs] src [12361] trunk/sys/sys: sync with FreeBSD 11-stable

[laffer1 at midnightbsd.org]

Revision: 12361
          http://svnweb.midnightbsd.org/src/?rev=12361
Author:   laffer1
Date:     2020-02-09 13:31:04 -0500 (Sun, 09 Feb 2020)
Log Message:
-----------
sync with FreeBSD 11-stable

Modified Paths:
--------------
    trunk/sys/sys/sdt.h
    trunk/sys/sys/seq.h

Modified: trunk/sys/sys/sdt.h
===================================================================
--- trunk/sys/sys/sdt.h	2020-02-09 18:30:15 UTC (rev 12360)
+++ trunk/sys/sys/sdt.h	2020-02-09 18:31:04 UTC (rev 12361)
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: stable/10/sys/sys/sdt.h 289795 2015-10-23 07:37:44Z avg $
+ * $FreeBSD: stable/11/sys/sys/sdt.h 331722 2018-03-29 02:50:57Z eadler $
  *
  * Statically Defined Tracing (SDT) definitions.
  *
@@ -81,6 +81,8 @@
 #include <sys/cdefs.h>
 #include <sys/linker_set.h>
 
+extern volatile bool sdt_probes_enabled;
+
 #ifndef KDTRACE_HOOKS
 
 #define SDT_PROVIDER_DEFINE(prov)
@@ -162,10 +164,12 @@
 	extern struct sdt_probe sdt_##prov##_##mod##_##func##_##name[1]
 
 #define SDT_PROBE(prov, mod, func, name, arg0, arg1, arg2, arg3, arg4)	do {	\
-	if (sdt_##prov##_##mod##_##func##_##name->id)				\
+	if (__predict_false(sdt_probes_enabled)) {				\
+		if (__predict_false(sdt_##prov##_##mod##_##func##_##name->id))	\
 		(*sdt_probe_func)(sdt_##prov##_##mod##_##func##_##name->id,	\
 		    (uintptr_t) arg0, (uintptr_t) arg1, (uintptr_t) arg2,	\
 		    (uintptr_t) arg3, (uintptr_t) arg4);			\
+	} \
 } while (0)
 
 #define SDT_PROBE_ARGTYPE(prov, mod, func, name, num, type, xtype)		\

Modified: trunk/sys/sys/seq.h
===================================================================
--- trunk/sys/sys/seq.h	2020-02-09 18:30:15 UTC (rev 12360)
+++ trunk/sys/sys/seq.h	2020-02-09 18:31:04 UTC (rev 12361)
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: stable/10/sys/sys/seq.h 273109 2014-10-14 21:19:23Z mjg $
+ * $FreeBSD: stable/11/sys/sys/seq.h 312714 2017-01-24 19:39:24Z mjg $
  */
 
 #ifndef _SYS_SEQ_H_
@@ -60,7 +60,6 @@
  * 		lobj = gobj;
  * 		if (seq_consistent(&gobj->seq, seq))
  * 			break;
- * 		cpu_spinwait();
  * 	}
  * 	foo(lobj);
  */		
@@ -70,25 +69,6 @@
 
 #include <machine/cpu.h>
 
-/*
- * This is a temporary hack until memory barriers are cleaned up.
- *
- * atomic_load_acq_int at least on amd64 provides a full memory barrier,
- * in a way which affects perforance.
- *
- * Hack below covers all architectures and avoids most of the penalty at least
- * on amd64.
- */
-static __inline int
-atomic_load_acq_rmb_int(volatile u_int *p)
-{
-	volatile u_int v;
-
-	v = *p;
-	atomic_load_acq_int(&v);
-	return (v);
-}
-
 static __inline bool
 seq_in_modify(seq_t seqp)
 {
@@ -101,7 +81,8 @@
 {
 
 	MPASS(!seq_in_modify(*seqp));
-	atomic_add_acq_int(seqp, 1);
+	*seqp += 1;
+	atomic_thread_fence_rel();
 }
 
 static __inline void
@@ -108,17 +89,17 @@
 seq_write_end(seq_t *seqp)
 {
 
-	atomic_add_rel_int(seqp, 1);
+	atomic_store_rel_int(seqp, *seqp + 1);
 	MPASS(!seq_in_modify(*seqp));
 }
 
 static __inline seq_t
-seq_read(seq_t *seqp)
+seq_read(const seq_t *seqp)
 {
 	seq_t ret;
 
 	for (;;) {
-		ret = atomic_load_acq_rmb_int(seqp);
+		ret = atomic_load_acq_int(__DECONST(seq_t *, seqp));
 		if (seq_in_modify(ret)) {
 			cpu_spinwait();
 			continue;
@@ -130,17 +111,18 @@
 }
 
 static __inline seq_t
-seq_consistent(seq_t *seqp, seq_t oldseq)
+seq_consistent_nomb(const seq_t *seqp, seq_t oldseq)
 {
 
-	return (atomic_load_acq_rmb_int(seqp) == oldseq);
+	return (*seqp == oldseq);
 }
 
 static __inline seq_t
-seq_consistent_nomb(seq_t *seqp, seq_t oldseq)
+seq_consistent(const seq_t *seqp, seq_t oldseq)
 {
 
-	return (*seqp == oldseq);
+	atomic_thread_fence_acq();
+	return (seq_consistent_nomb(seqp, oldseq));
 }
 
 #endif	/* _KERNEL */