6740460 Dom0 hangs while running libsched - no resources to continue

4 files changed, 17 insertions, 9 deletions

diff --git a/usr/src/uts/i86pc/os/intr.c b/usr/src/uts/i86pc/os/intr.c
index 4f9f7f2f4b..786cd29e8f 100644
--- a/usr/src/uts/i86pc/os/intr.c
+++ b/usr/src/uts/i86pc/os/intr.c
@@ -934,6 +934,8 @@ do_interrupt(struct regs *rp, trap_trace_rec_t *ttp)
 
 	cpu_idle_exit(CPU_IDLE_CB_FLAG_INTR);
 
+	++*(uint16_t *)&cpu->cpu_m.mcpu_istamp;
+
 	/*
 	 * If it's a softint go do it now.
 	 */
diff --git a/usr/src/uts/i86pc/os/mp_startup.c b/usr/src/uts/i86pc/os/mp_startup.c
index d9369d0b5c..0ba377f67c 100644
--- a/usr/src/uts/i86pc/os/mp_startup.c
+++ b/usr/src/uts/i86pc/os/mp_startup.c
@@ -258,6 +258,8 @@ mp_startup_init(int cpun)
 #endif
 		cp->cpu_m.mcpu_idle_cpu = cpu_idle;
 
+	cp->cpu_m.mcpu_istamp = cpun << 16;
+
 	procp = curthread->t_procp;
 
 	mutex_enter(&cpu_lock);
diff --git a/usr/src/uts/i86pc/sys/machcpuvar.h b/usr/src/uts/i86pc/sys/machcpuvar.h
index 955468a714..b652331715 100644
--- a/usr/src/uts/i86pc/sys/machcpuvar.h
+++ b/usr/src/uts/i86pc/sys/machcpuvar.h
@@ -136,6 +136,15 @@ struct	machcpu {
 	struct cpu_ucode_info	*mcpu_ucode_info;
 
 	void		*mcpu_pm_mach_state;
+
+	/*
+	 * A stamp that is unique per processor and changes
+	 * whenever an interrupt happens. Userful for detecting
+	 * if a section of code gets interrupted.
+	 * The high order 16 bits will hold the cpu->cpu_id.
+	 * The low order bits will be incremented on every interrupt.
+	 */
+	volatile uint32_t	mcpu_istamp;
 };
 
 #define	NINTR_THREADS	(LOCK_LEVEL-1)	/* number of interrupt threads */
diff --git a/usr/src/uts/i86xpv/os/xpv_timestamp.c b/usr/src/uts/i86xpv/os/xpv_timestamp.c
index da7f263a6f..d7d13f984b 100644
--- a/usr/src/uts/i86xpv/os/xpv_timestamp.c
+++ b/usr/src/uts/i86xpv/os/xpv_timestamp.c
@@ -87,14 +87,9 @@ dtrace_xpv_getsystime(void)
 	vcpu_time_info_t *src;
 	vcpu_time_info_t __vti, *dst = &__vti;
 	uint64_t tsc_delta;
-	kthread_t *t = curthread;
 	uint64_t tsc;
 	hrtime_t result;
-
-	/*
-	 * This stops us from wandering off the virtual cpu.
-	 */
-	t->t_preempt++;
+	uint32_t stamp;
 
 	src = &CPU->cpu_m.mcpu_vcpu_info->time;
 
@@ -104,6 +99,7 @@ dtrace_xpv_getsystime(void)
 	 */
 	do {
 		dst->version = src->version;
+		stamp = CPU->cpu_m.mcpu_istamp;
 
 		membar_consumer();
 
@@ -122,7 +118,8 @@ dtrace_xpv_getsystime(void)
 
 		membar_consumer();
 
-	} while ((src->version & 1) | (dst->version ^ src->version));
+	} while (((src->version & 1) | (dst->version ^ src->version)) ||
+	    CPU->cpu_m.mcpu_istamp != stamp);
 
 	if (dst->tsc_shift >= 0)
 		tsc_delta <<= dst->tsc_shift;
@@ -132,8 +129,6 @@ dtrace_xpv_getsystime(void)
 	result = dst->system_time +
 	    ((uint64_t)(tsc_delta * (uint64_t)dst->tsc_to_system_mul) >> 32);
 
-	t->t_preempt--;
-
 	return (result);
 }