- Add a td_pflags field to struct thread for private flags accessed only by

  curthread.  Unlike td_flags, this field does not need any locking.
- Replace the td_inktr and td_inktrace variables with equivalent private
  thread flags.
- Move TDF_OLDMASK over to the private flags field so it no longer requires
  sched_lock.

5 files changed, 27 insertions, 29 deletions

diff --git a/sys/kern/kern_ktr.c b/sys/kern/kern_ktr.c
index 2454406..7c50790 100644
--- a/sys/kern/kern_ktr.c
+++ b/sys/kern/kern_ktr.c
@@ -188,9 +188,9 @@ ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
 		return;
 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
 	td = curthread;
-	if (td->td_inktr)
+	if (td->td_pflags & TDP_INKTR)
 		return;
-	td->td_inktr++;
+	td->td_pflags |= TDP_INKTR;
 #endif
 #ifdef KTR_ALQ
 	if (ktr_alq_enabled &&
@@ -247,7 +247,7 @@ ktr_tracepoint(u_int mask, const char *file, int line, const char *format,
 done:
 #endif
 #if defined(KTR_VERBOSE) || defined(KTR_ALQ)
-	td->td_inktr--;
+	td->td_pflags &= ~TDP_INKTR;
 #endif
 }
 
diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 8e97122..ecb2421 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -157,12 +157,12 @@ sysctl_kern_ktrace_request_pool(SYSCTL_HANDLER_ARGS)
 	if (error)
 		return (error);
 	td = curthread;
-	td->td_inktrace = 1;
+	td->td_pflags |= TDP_INKTRACE;
 	mtx_lock(&ktrace_mtx);
 	oldsize = ktr_requestpool;
 	newsize = ktrace_resize_pool(wantsize);
 	mtx_unlock(&ktrace_mtx);
-	td->td_inktrace = 0;
+	td->td_pflags &= ~TDP_INKTRACE;
 	error = SYSCTL_OUT(req, &oldsize, sizeof(uint));
 	if (error)
 		return (error);
@@ -215,11 +215,11 @@ ktr_getrequest(int type)
 	struct proc *p = td->td_proc;
 	int pm;
 
-	td->td_inktrace = 1;
+	td->td_pflags |= TDP_INKTRACE;
 	mtx_lock(&ktrace_mtx);
 	if (!KTRCHECK(td, type)) {
 		mtx_unlock(&ktrace_mtx);
-		td->td_inktrace = 0;
+		td->td_pflags &= ~TDP_INKTRACE;
 		return (NULL);
 	}
 	req = STAILQ_FIRST(&ktr_free);
@@ -248,7 +248,7 @@ ktr_getrequest(int type)
 		mtx_unlock(&ktrace_mtx);
 		if (pm)
 			printf("Out of ktrace request objects.\n");
-		td->td_inktrace = 0;
+		td->td_pflags &= ~TDP_INKTRACE;
 	}
 	return (req);
 }
@@ -261,7 +261,7 @@ ktr_submitrequest(struct ktr_request *req)
 	STAILQ_INSERT_TAIL(&ktr_todo, req, ktr_list);
 	sema_post(&ktrace_sema);
 	mtx_unlock(&ktrace_mtx);
-	curthread->td_inktrace = 0;
+	curthread->td_pflags &= ~TDP_INKTRACE;
 }
 
 static void
@@ -514,7 +514,7 @@ ktrace(td, uap)
 	if (ops != KTROP_CLEARFILE && facs == 0)
 		return (EINVAL);
 
-	td->td_inktrace = 1;
+	td->td_pflags |= TDP_INKTRACE;
 	if (ops != KTROP_CLEAR) {
 		/*
 		 * an operation which requires a file argument.
@@ -525,7 +525,7 @@ ktrace(td, uap)
 		error = vn_open(&nd, &flags, 0);
 		if (error) {
 			mtx_unlock(&Giant);
-			td->td_inktrace = 0;
+			td->td_pflags &= ~TDP_INKTRACE;
 			return (error);
 		}
 		NDFREE(&nd, NDF_ONLY_PNBUF);
@@ -534,7 +534,7 @@ ktrace(td, uap)
 		if (vp->v_type != VREG) {
 			(void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
 			mtx_unlock(&Giant);
-			td->td_inktrace = 0;
+			td->td_pflags &= ~TDP_INKTRACE;
 			return (EACCES);
 		}
 		mtx_unlock(&Giant);
@@ -623,7 +623,7 @@ done:
 		(void) vn_close(vp, FWRITE, td->td_ucred, td);
 		mtx_unlock(&Giant);
 	}
-	td->td_inktrace = 0;
+	td->td_pflags &= ~TDP_INKTRACE;
 	return (error);
 #else /* !KTRACE */
 	return (ENOSYS);
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index ef4948f..6126f5f 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -874,7 +874,7 @@ out:
 		mtx_unlock(&ps->ps_mtx);
 #ifdef KTRACE
 		if (KTRPOINT(td, KTR_PSIG))
-			ktrpsig(sig, action, td->td_flags & TDF_OLDMASK ?
+			ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
 			    &td->td_oldsigmask : &td->td_sigmask, 0);
 #endif
 		_STOPEVENT(p, S_SIG, sig);
@@ -1089,9 +1089,7 @@ kern_sigsuspend(struct thread *td, sigset_t mask)
 	 */
 	PROC_LOCK(p);
 	td->td_oldsigmask = td->td_sigmask;
-	mtx_lock_spin(&sched_lock);
-	td->td_flags |= TDF_OLDMASK;
-	mtx_unlock_spin(&sched_lock);
+	td->td_pflags |= TDP_OLDMASK;
 	SIG_CANTMASK(mask);
 	td->td_sigmask = mask;
 	signotify(td);
@@ -1122,9 +1120,7 @@ osigsuspend(td, uap)
 
 	PROC_LOCK(p);
 	td->td_oldsigmask = td->td_sigmask;
-	mtx_lock_spin(&sched_lock);
-	td->td_flags |= TDF_OLDMASK;
-	mtx_unlock_spin(&sched_lock);
+	td->td_pflags |= TDP_OLDMASK;
 	OSIG2SIG(uap->mask, mask);
 	SIG_CANTMASK(mask);
 	SIGSETLO(td->td_sigmask, mask);
@@ -2136,7 +2132,7 @@ postsig(sig)
 	action = ps->ps_sigact[_SIG_IDX(sig)];
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_PSIG))
-		ktrpsig(sig, action, td->td_flags & TDF_OLDMASK ?
+		ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
 		    &td->td_oldsigmask : &td->td_sigmask, 0);
 #endif
 	_STOPEVENT(p, S_SIG, sig);
@@ -2164,11 +2160,9 @@ postsig(sig)
 		 * mask from before the sigsuspend is what we want
 		 * restored after the signal processing is completed.
 		 */
-		if (td->td_flags & TDF_OLDMASK) {
+		if (td->td_pflags & TDP_OLDMASK) {
 			returnmask = td->td_oldsigmask;
-			mtx_lock_spin(&sched_lock);
-			td->td_flags &= ~TDF_OLDMASK;
-			mtx_unlock_spin(&sched_lock);
+			td->td_pflags &= ~TDP_OLDMASK;
 		} else
 			returnmask = td->td_sigmask;
 
diff --git a/sys/sys/ktrace.h b/sys/sys/ktrace.h
index 8fffcaf..cff0e91 100644
--- a/sys/sys/ktrace.h
+++ b/sys/sys/ktrace.h
@@ -70,7 +70,8 @@ struct ktr_header {
  * is the public interface.
  */
 #define	KTRCHECK(td, type)	((td)->td_proc->p_traceflag & (1 << type))
-#define KTRPOINT(td, type)	(KTRCHECK((td), (type)) && !(td)->td_inktrace)
+#define KTRPOINT(td, type)						\
+	(KTRCHECK((td), (type)) && !((td)->td_pflags & TDP_INKTRACE))
 
 /*
  * ktrace record types
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 125e690..dec25e5 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -269,14 +269,13 @@ struct thread {
 #define	td_startzero td_flags
 	int		td_flags;	/* (j) TDF_* flags. */
 	int		td_inhibitors;	/* (j) Why can not run */
+	int		td_pflags;	/* (k) Private thread (TDP_*) flags. */
 	struct kse	*td_last_kse;	/* (j) Previous value of td_kse */
 	struct kse	*td_kse;	/* (j) Current KSE if running. */
 	int		td_dupfd;	/* (k) Ret value from fdopen. XXX */
 	void		*td_wchan;	/* (j) Sleep address. */
 	const char	*td_wmesg;	/* (j) Reason for sleep. */
 	u_char		td_lastcpu;	/* (j) Last cpu we were on. */
-	u_char		td_inktr;	/* (k) Currently handling a KTR. */
-	u_char		td_inktrace;	/* (k) Currently handling a KTRACE. */
 	u_char		td_oncpu;	/* (j) Which cpu we are on. */
 	short		td_locks;	/* (k) DEBUG: lockmgr count of locks */
 	struct mtx	*td_blocked;	/* (j) Mutex process is blocked on. */
@@ -333,7 +332,6 @@ struct thread {
 	struct td_sched	*td_sched;	/* (*) Scheduler specific data */
 };
 /* flags kept in td_flags */ 
-#define	TDF_OLDMASK	0x000001 /* Need to restore mask after suspend. */
 #define	TDF_INPANIC	0x000002 /* Caused a panic, let it drive crashdump. */
 #define	TDF_CAN_UNBIND	0x000004 /* Only temporarily bound. */
 #define	TDF_SINTR	0x000008 /* Sleep is interruptible. */
@@ -352,6 +350,11 @@ struct thread {
 #define	TDF_NEEDSIGCHK	0x020000 /* Thread may need signal delivery. */
 #define	TDF_DEADLKTREAT	0x800000 /* Lock aquisition - deadlock treatment. */
 
+/* "private" flags kept in td_pflags */
+#define	TDP_OLDMASK	0x0001 /* Need to restore mask after suspend. */
+#define	TDP_INKTR	0x0002 /* Thread is currently in KTR code. */
+#define	TDP_INKTRACE	0x0004 /* Thread is currently in KTRACE code. */
+
 #define	TDI_SUSPENDED	0x0001	/* On suspension queue. */
 #define	TDI_SLEEPING	0x0002	/* Actually asleep! (tricky). */
 #define	TDI_SWAPPED	0x0004	/* Stack not in mem.. bad juju if run. */