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| author | Thomas Gleixner <tglx@linutronix.de> | 2016-03-08 10:36:13 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-03-12 20:57:38 +0100 |
| commit | d10ef6f9380b8853c4b48eb104268fccfdc0b0c5 (patch) | |
| tree | fa8c286cb350bbc211cc79d93fc33888acf903a3 /kernel/cpu.c | |
| parent | cpu/hotplug: Fix smpboot thread ordering (diff) | |
| download | linux-d10ef6f9380b8853c4b48eb104268fccfdc0b0c5.tar.xz linux-d10ef6f9380b8853c4b48eb104268fccfdc0b0c5.zip | |
cpu/hotplug: Document states better
Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index bcee286b7c73..6ea42e8da861 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1172,6 +1172,10 @@ static struct cpuhp_step cpuhp_bp_states[] = { .teardown = NULL, .cant_stop = true, }, + /* + * Preparatory and dead notifiers. Will be replaced once the notifiers + * are converted to states. + */ [CPUHP_NOTIFY_PREPARE] = { .name = "notify:prepare", .startup = notify_prepare, @@ -1179,12 +1183,17 @@ static struct cpuhp_step cpuhp_bp_states[] = { .skip_onerr = true, .cant_stop = true, }, + /* Kicks the plugged cpu into life */ [CPUHP_BRINGUP_CPU] = { .name = "cpu:bringup", .startup = bringup_cpu, .teardown = NULL, .cant_stop = true, }, + /* + * Handled on controll processor until the plugged processor manages + * this itself. + */ [CPUHP_TEARDOWN_CPU] = { .name = "cpu:teardown", .startup = NULL, @@ -1197,6 +1206,23 @@ static struct cpuhp_step cpuhp_bp_states[] = { /* 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", + }, + /* + * Last state before CPU enters the idle loop to die. Transient state + * for synchronization. + */ + [CPUHP_AP_OFFLINE] = { + .name = "ap:offline", + .cant_stop = true, + }, + /* + * Low level startup/teardown notifiers. Run with interrupts + * disabled. Will be removed once the notifiers are converted to + * states. + */ [CPUHP_AP_NOTIFY_STARTING] = { .name = "notify:starting", .startup = notify_starting, @@ -1204,17 +1230,32 @@ static struct cpuhp_step cpuhp_ap_states[] = { .skip_onerr = true, .cant_stop = true, }, + /* Entry state on starting. Interrupts enabled from here on. Transient + * state for synchronsization */ + [CPUHP_AP_ONLINE] = { + .name = "ap:online", + }, + /* Handle smpboot threads park/unpark */ [CPUHP_AP_SMPBOOT_THREADS] = { .name = "smpboot:threads", .startup = smpboot_unpark_threads, .teardown = NULL, }, + /* + * Online/down_prepare notifiers. Will be removed once the notifiers + * are converted to states. + */ [CPUHP_AP_NOTIFY_ONLINE] = { .name = "notify:online", .startup = notify_online, .teardown = notify_down_prepare, }, #endif + /* + * The dynamically registered state space is here + */ + + /* CPU is fully up and running. */ [CPUHP_ONLINE] = { .name = "online", .startup = NULL, @@ -1232,7 +1273,11 @@ static int cpuhp_cb_check(enum cpuhp_state state) static bool cpuhp_is_ap_state(enum cpuhp_state state) { - return state > CPUHP_BRINGUP_CPU; + /* + * The extra check for CPUHP_TEARDOWN_CPU is only for documentation + * purposes as that state is handled explicitely in cpu_down. + */ + return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; } static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |