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
@@ -448,23 +448,6 @@
 	return (0);
 }
 
-/*
- * XXX don't know what we should do here.
- */
-static int
-arm64_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return (0);
-}
-
-static int
-arm64_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return (0);
-}
-
 static int
 arm64_pcpu_init(struct pmc_mdep *md, int cpu)
 {
@@ -614,11 +597,8 @@
 	pcd->pcd_stop_pmc       = arm64_stop_pmc;
 	pcd->pcd_write_pmc      = arm64_write_pmc;
 
-	pmc_mdep->pmd_intr       = arm64_intr;
-	pmc_mdep->pmd_switch_in  = arm64_switch_in;
-	pmc_mdep->pmd_switch_out = arm64_switch_out;
-
-	pmc_mdep->pmd_npmc   += arm64_npmcs;
+	pmc_mdep->pmd_intr = arm64_intr;
+	pmc_mdep->pmd_npmc += arm64_npmcs;
 
 #ifdef DEV_ACPI
 	if (pmc_cmn600_nclasses() > 0)
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
@@ -416,23 +416,6 @@
 	return 0;
 }
 
-/*
- * XXX don't know what we should do here.
- */
-static int
-armv7_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return 0;
-}
-
-static int
-armv7_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return 0;
-}
-
 static int
 armv7_pcpu_init(struct pmc_mdep *md, int cpu)
 {
@@ -551,11 +534,8 @@
 	pcd->pcd_stop_pmc       = armv7_stop_pmc;
 	pcd->pcd_write_pmc      = armv7_write_pmc;
 
-	pmc_mdep->pmd_intr       = armv7_intr;
-	pmc_mdep->pmd_switch_in  = armv7_switch_in;
-	pmc_mdep->pmd_switch_out = armv7_switch_out;
-	
-	pmc_mdep->pmd_npmc   += armv7_npmcs;
+	pmc_mdep->pmd_intr = armv7_intr;
+	pmc_mdep->pmd_npmc += armv7_npmcs;
 
 	return (pmc_mdep);
 }
diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c
--- a/sys/dev/hwpmc/hwpmc_mod.c
+++ b/sys/dev/hwpmc/hwpmc_mod.c
@@ -5453,6 +5453,10 @@
 	    sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO);
 	md->pmd_nclass = n;
 
+	/* Default methods */
+	md->pmd_switch_in = generic_switch_in;
+	md->pmd_switch_out = generic_switch_out;
+
 	/* Add base class. */
 	pmc_soft_initialize(md);
 	return md;
@@ -5490,9 +5494,6 @@
 
 	md->pmd_cputype    = PMC_CPU_GENERIC;
 
-	md->pmd_switch_in  = generic_switch_in;
-	md->pmd_switch_out = generic_switch_out;
-
 	return (md);
 }
 
diff --git a/sys/dev/hwpmc/hwpmc_powerpc.c b/sys/dev/hwpmc/hwpmc_powerpc.c
--- a/sys/dev/hwpmc/hwpmc_powerpc.c
+++ b/sys/dev/hwpmc/hwpmc_powerpc.c
@@ -105,20 +105,6 @@
 	return (frames);
 }
 
-static int
-powerpc_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return (0);
-}
-
-static int
-powerpc_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
-{
-
-	return (0);
-}
-
 int
 powerpc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
 {
@@ -564,9 +550,6 @@
 
 	vers = mfpvr() >> 16;
 
-	pmc_mdep->pmd_switch_in  = powerpc_switch_in;
-	pmc_mdep->pmd_switch_out = powerpc_switch_out;
-	
 	switch (vers) {
 	case MPC7447A:
 	case MPC7448: