From 2cba8dd301342c1c31f6dbf496e8351fa8359584 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Tue, 4 Nov 2014 16:35:56 +0000
Subject: Add a new thread state "spinning" to schedgraph and add tracepoints
 at the start and stop of spinning waits in lock primitives.

---
 sys/kern/kern_sx.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'sys/kern/kern_sx.c')

diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c
index 8154b20c494e..6bd276077309 100644
--- a/sys/kern/kern_sx.c
+++ b/sys/kern/kern_sx.c
@@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/sched.h>
 #include <sys/sleepqueue.h>
 #include <sys/sx.h>
 #include <sys/sysctl.h>
@@ -555,6 +556,10 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file,
 						CTR3(KTR_LOCK,
 					    "%s: spinning on %p held by %p",
 						    __func__, sx, owner);
+					KTR_STATE1(KTR_SCHED, "thread",
+					    sched_tdname(curthread), "spinning",
+					    "lockname:\"%s\"",
+					    sx->lock_object.lo_name);
 					GIANT_SAVE();
 					while (SX_OWNER(sx->sx_lock) == x &&
 					    TD_IS_RUNNING(owner)) {
@@ -563,9 +568,14 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file,
 						spin_cnt++;
 #endif
 					}
+					KTR_STATE0(KTR_SCHED, "thread",
+					    sched_tdname(curthread), "running");
 					continue;
 				}
 			} else if (SX_SHARERS(x) && spintries < asx_retries) {
+				KTR_STATE1(KTR_SCHED, "thread",
+				    sched_tdname(curthread), "spinning",
+				    "lockname:\"%s\"", sx->lock_object.lo_name);
 				GIANT_SAVE();
 				spintries++;
 				for (i = 0; i < asx_loops; i++) {
@@ -582,6 +592,8 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file,
 					spin_cnt++;
 #endif
 				}
+				KTR_STATE0(KTR_SCHED, "thread",
+				    sched_tdname(curthread), "running");
 				if (i != asx_loops)
 					continue;
 			}
@@ -844,6 +856,9 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line)
 					CTR3(KTR_LOCK,
 					    "%s: spinning on %p held by %p",
 					    __func__, sx, owner);
+				KTR_STATE1(KTR_SCHED, "thread",
+				    sched_tdname(curthread), "spinning",
+				    "lockname:\"%s\"", sx->lock_object.lo_name);
 				GIANT_SAVE();
 				while (SX_OWNER(sx->sx_lock) == x &&
 				    TD_IS_RUNNING(owner)) {
@@ -852,6 +867,8 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line)
 #endif
 					cpu_spinwait();
 				}
+				KTR_STATE0(KTR_SCHED, "thread",
+				    sched_tdname(curthread), "running");
 				continue;
 			}
 		}
-- 
cgit v1.2.3