svn commit: r284020 - stable/10/sys/kern

[Konstantin Belousov]

Author: kib
Date: Fri Jun  5 08:26:38 2015
New Revision: 284020
URL: https://svnweb.freebsd.org/changeset/base/284020

Log:
  MFC r283745:
  Do not raise priority of the idle thread on singal delivery.

Modified:
  stable/10/sys/kern/kern_sig.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/kern_sig.c
==============================================================================
--- stable/10/sys/kern/kern_sig.c	Fri Jun  5 08:23:33 2015	(r284019)
+++ stable/10/sys/kern/kern_sig.c	Fri Jun  5 08:26:38 2015	(r284020)
@@ -2371,9 +2371,12 @@ tdsigwakeup(struct thread *td, int sig, 
 	thread_lock(td);
 	/*
 	 * Bring the priority of a thread up if we want it to get
-	 * killed in this lifetime.
+	 * killed in this lifetime.  Be careful to avoid bumping the
+	 * priority of the idle thread, since we still allow to signal
+	 * kernel processes.
 	 */
-	if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER)
+	if (action == SIG_DFL && (prop & SA_KILL) != 0 &&
+	    td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
 		sched_prio(td, PUSER);
 	if (TD_ON_SLEEPQ(td)) {
 		/*
@@ -2411,7 +2414,7 @@ tdsigwakeup(struct thread *td, int sig, 
 		/*
 		 * Give low priority threads a better chance to run.
 		 */
-		if (td->td_priority > PUSER)
+		if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
 			sched_prio(td, PUSER);
 
 		wakeup_swapper = sleepq_abort(td, intrval);