diff --git a/sys/dev/hwpmc/hwpmc_arm64.c b/sys/dev/hwpmc/hwpmc_arm64.c
--- a/sys/dev/hwpmc/hwpmc_arm64.c
+++ b/sys/dev/hwpmc/hwpmc_arm64.c
@@ -215,12 +215,12 @@
 		/* Clear Overflow Flag */
 		WRITE_SPECIALREG(pmovsclr_el0, reg);
 		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
-			pm->pm_overflowcnt++;
+			pm->pm_pcpu_state[cpu].pps_overflowcnt++;
 
 		/* Reread counter in case we raced. */
 		tmp = arm64_pmcn_read(ri);
 	}
-	tmp += 0x100000000llu * pm->pm_overflowcnt;
+	tmp += 0x100000000llu * pm->pm_pcpu_state[cpu].pps_overflowcnt;
 	intr_restore(s);
 
 	PMCDBG2(MDP, REA, 2, "arm64-read id=%d -> %jd", ri, tmp);
@@ -249,7 +249,7 @@
 
 	PMCDBG3(MDP, WRI, 1, "arm64-write cpu=%d ri=%d v=%jx", cpu, ri, v);
 
-	pm->pm_overflowcnt = v >> 32;
+	pm->pm_pcpu_state[cpu].pps_overflowcnt = v >> 32;
 	arm64_pmcn_write(ri, v);
 
 	return 0;
@@ -373,7 +373,7 @@
 		retval = 1; /* Found an interrupting PMC. */
 
 		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
-			pm->pm_overflowcnt += 1;
+			pm->pm_pcpu_state[cpu].pps_overflowcnt += 1;
 			continue;
 		}
 
diff --git a/sys/dev/hwpmc/hwpmc_armv7.c b/sys/dev/hwpmc/hwpmc_armv7.c
--- a/sys/dev/hwpmc/hwpmc_armv7.c
+++ b/sys/dev/hwpmc/hwpmc_armv7.c
@@ -192,12 +192,12 @@
 		/* Clear Overflow Flag */
 		cp15_pmovsr_set(reg);
 		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
-			pm->pm_overflowcnt += 1;
+			pm->pm_pcpu_state[cpu].pps_overflowcnt++;
 
 		/* Reread counter in case we raced. */
 		tmp = armv7_pmcn_read(ri, pm->pm_md.pm_armv7.pm_armv7_evsel);
 	}
-	tmp += 0x100000000llu * pm->pm_overflowcnt;
+	tmp += 0x100000000llu * pm->pm_pcpu_state[cpu].pps_overflowcnt;
 	intr_restore(s);
 
 	PMCDBG2(MDP, REA, 2, "armv7-read id=%d -> %jd", ri, tmp);
@@ -226,7 +226,7 @@
 	
 	PMCDBG3(MDP, WRI, 1, "armv7-write cpu=%d ri=%d v=%jx", cpu, ri, v);
 
-	pm->pm_overflowcnt = v >> 32;
+	pm->pm_pcpu_state[cpu].pps_overflowcnt = v >> 32;
 	if (pm->pm_md.pm_armv7.pm_armv7_evsel == PMC_EV_CPU_CYCLES)
 		cp15_pmccntr_set(v);
 	else
@@ -363,7 +363,7 @@
 		retval = 1; /* Found an interrupting PMC. */
 
 		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
-			pm->pm_overflowcnt += 1;
+			pm->pm_pcpu_state[cpu].pps_overflowcnt += 1;
 			continue;
 		}
 		if (pm->pm_state != PMC_STATE_RUNNING)
diff --git a/sys/sys/pmc.h b/sys/sys/pmc.h
--- a/sys/sys/pmc.h
+++ b/sys/sys/pmc.h
@@ -729,6 +729,7 @@
  *
  */
 struct pmc_pcpu_state {
+	uint32_t pps_overflowcnt;	/* count overflow interrupts */
 	uint8_t pps_stalled;
 	uint8_t pps_cpustate;
 } __aligned(CACHE_LINE_SIZE);
@@ -773,7 +774,6 @@
 	struct pmc_owner *pm_owner;	/* owner thread state */
 	counter_u64_t		pm_runcount;	/* #cpus currently on */
 	enum pmc_state	pm_state;	/* current PMC state */
-	uint32_t	pm_overflowcnt;	/* count overflow interrupts */
 
 	/*
 	 * The PMC ID field encodes the row-index for the PMC, its