Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 2 Apr 2018 20:37:05 +0000 (13:37 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 2 Apr 2018 20:37:05 +0000 (13:37 -0700)
Pull SMP hotplug updates from Ingo Molnar:
 "Simplify the CPU hot-plug state machine"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Fix unused function warning
  cpu/hotplug: Merge cpuhp_bp_states and cpuhp_ap_states

kernel/cpu.c

index 53f7dc65f9a3b917c1c347834257cf26521eff95..0db8938fbb236e58284927040e19998718ae74e7 100644 (file)
@@ -124,24 +124,11 @@ struct cpuhp_step {
 };
 
 static DEFINE_MUTEX(cpuhp_state_mutex);
-static struct cpuhp_step cpuhp_bp_states[];
-static struct cpuhp_step cpuhp_ap_states[];
-
-static bool cpuhp_is_ap_state(enum cpuhp_state state)
-{
-       /*
-        * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
-        * purposes as that state is handled explicitly in cpu_down.
-        */
-       return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
-}
+static struct cpuhp_step cpuhp_hp_states[];
 
 static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
 {
-       struct cpuhp_step *sp;
-
-       sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
-       return sp + state;
+       return cpuhp_hp_states + state;
 }
 
 /**
@@ -239,6 +226,15 @@ err:
 }
 
 #ifdef CONFIG_SMP
+static bool cpuhp_is_ap_state(enum cpuhp_state state)
+{
+       /*
+        * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
+        * purposes as that state is handled explicitly in cpu_down.
+        */
+       return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
+}
+
 static inline void wait_for_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
 {
        struct completion *done = bringup ? &st->done_up : &st->done_down;
@@ -1224,7 +1220,7 @@ int __boot_cpu_id;
 #endif /* CONFIG_SMP */
 
 /* Boot processor state steps */
-static struct cpuhp_step cpuhp_bp_states[] = {
+static struct cpuhp_step cpuhp_hp_states[] = {
        [CPUHP_OFFLINE] = {
                .name                   = "offline",
                .startup.single         = NULL,
@@ -1289,24 +1285,6 @@ static struct cpuhp_step cpuhp_bp_states[] = {
                .teardown.single        = NULL,
                .cant_stop              = true,
        },
-       /*
-        * Handled on controll processor until the plugged processor manages
-        * this itself.
-        */
-       [CPUHP_TEARDOWN_CPU] = {
-               .name                   = "cpu:teardown",
-               .startup.single         = NULL,
-               .teardown.single        = takedown_cpu,
-               .cant_stop              = true,
-       },
-#else
-       [CPUHP_BRINGUP_CPU] = { },
-#endif
-};
-
-/* Application processor state steps */
-static struct cpuhp_step cpuhp_ap_states[] = {
-#ifdef CONFIG_SMP
        /* Final state before CPU kills itself */
        [CPUHP_AP_IDLE_DEAD] = {
                .name                   = "idle:dead",
@@ -1340,6 +1318,16 @@ static struct cpuhp_step cpuhp_ap_states[] = {
        [CPUHP_AP_ONLINE] = {
                .name                   = "ap:online",
        },
+       /*
+        * Handled on controll processor until the plugged processor manages
+        * this itself.
+        */
+       [CPUHP_TEARDOWN_CPU] = {
+               .name                   = "cpu:teardown",
+               .startup.single         = NULL,
+               .teardown.single        = takedown_cpu,
+               .cant_stop              = true,
+       },
        /* Handle smpboot threads park/unpark */
        [CPUHP_AP_SMPBOOT_THREADS] = {
                .name                   = "smpboot/threads:online",
@@ -1408,11 +1396,11 @@ static int cpuhp_reserve_state(enum cpuhp_state state)
 
        switch (state) {
        case CPUHP_AP_ONLINE_DYN:
-               step = cpuhp_ap_states + CPUHP_AP_ONLINE_DYN;
+               step = cpuhp_hp_states + CPUHP_AP_ONLINE_DYN;
                end = CPUHP_AP_ONLINE_DYN_END;
                break;
        case CPUHP_BP_PREPARE_DYN:
-               step = cpuhp_bp_states + CPUHP_BP_PREPARE_DYN;
+               step = cpuhp_hp_states + CPUHP_BP_PREPARE_DYN;
                end = CPUHP_BP_PREPARE_DYN_END;
                break;
        default: