From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Thu, 21 Feb 2013 23:32:12 +0000 (-0800)
Subject: kernel - Add critical section in lwkt_yield_quick()
X-Git-Tag: v3.4.0rc~248
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/9c99cb336b475c5531fb726194c7f03049740570

kernel - Add critical section in lwkt_yield_quick()

* Add a critical section to protect the clearing of the LWKT reschedule
  bit against gd_tdrunq.
---

diff --git a/sys/kern/lwkt_thread.c b/sys/kern/lwkt_thread.c
index b7979a0171..27fd4d775c 100644
--- a/sys/kern/lwkt_thread.c
+++ b/sys/kern/lwkt_thread.c
@@ -1178,12 +1178,14 @@ lwkt_yield_quick(void)
     if ((gd->gd_reqflags & RQF_IDLECHECK_MASK) && td->td_nest_count < 2)
 	splz();
     if (lwkt_resched_wanted()) {
+	crit_enter();
 	if (TAILQ_FIRST(&gd->gd_tdrunq) == td) {
 	    clear_lwkt_resched();
 	} else {
 	    lwkt_schedule_self(curthread);
 	    lwkt_switch();
 	}
+	crit_exit();
     }
 }