[RFC v0 8/9] cpu: Do not set CPU_TASKS_FROZEN anymore

From: Daniel Wagner
Date: Fri Sep 04 2015 - 09:35:24 EST


There is no user left of CPU_TASKS_FROZEN, so we can stop propagating
this information.

Signed-off-by: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
include/linux/cpu.h | 15 ---------------
kernel/cpu.c | 22 ++++++++--------------
2 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 381ea8a..ebd07e7 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -104,21 +104,6 @@ enum {
#define CPU_DEAD_TIMEOUT 0x000D /* CPU (unsigned)v surviving CPU timed
out */

-/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
- * operation in progress
- */
-#define CPU_TASKS_FROZEN 0x0010
-
-#define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
-#define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
-#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
-#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
-#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
-#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
-
-
#ifdef CONFIG_SMP
/* Need to know about CPUs going up/down? */
#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e37442d..1f0408c 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -29,7 +29,6 @@
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
-static bool cpuhp_tasks_frozen;

/*
* The following two APIs (cpu_maps_update_begin/done) must be used when
@@ -224,12 +223,11 @@ int __register_cpu_notifier(struct notifier_block *nb)
static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
int *nr_calls)
{
- unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
void *hcpu = (void *)(long)cpu;

int ret;

- ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
+ ret = __raw_notifier_call_chain(&cpu_chain, val, hcpu, nr_to_call,
nr_calls);

return notifier_to_errno(ret);
@@ -347,7 +345,7 @@ static int take_cpu_down(void *_param)
}

/* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu, int tasks_frozen)
+static int _cpu_down(unsigned int cpu)
{
int err, nr_calls = 0;

@@ -359,8 +357,6 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)

cpu_hotplug_begin();

- cpuhp_tasks_frozen = tasks_frozen;
-
err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
if (err) {
nr_calls--;
@@ -448,7 +444,7 @@ int cpu_down(unsigned int cpu)
goto out;
}

- err = _cpu_down(cpu, 0);
+ err = _cpu_down(cpu);

out:
cpu_maps_update_done();
@@ -465,7 +461,7 @@ static int smpboot_thread_call(struct notifier_block *nfb,
{
int cpu = (long)hcpu;

- switch (action & ~CPU_TASKS_FROZEN) {
+ switch (action) {

case CPU_DOWN_FAILED:
case CPU_ONLINE:
@@ -490,7 +486,7 @@ void smpboot_thread_init(void)
}

/* Requires cpu_add_remove_lock to be held */
-static int _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu)
{
struct task_struct *idle;
int ret, nr_calls = 0;
@@ -512,8 +508,6 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
if (ret)
goto out;

- cpuhp_tasks_frozen = tasks_frozen;
-
ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
if (ret) {
nr_calls--;
@@ -565,7 +559,7 @@ int cpu_up(unsigned int cpu)
goto out;
}

- err = _cpu_up(cpu, 0);
+ err = _cpu_up(cpu);

out:
cpu_maps_update_done();
@@ -593,7 +587,7 @@ int disable_nonboot_cpus(void)
if (cpu == first_cpu)
continue;
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
- error = _cpu_down(cpu, 1);
+ error = _cpu_down(cpu);
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
@@ -643,7 +637,7 @@ void enable_nonboot_cpus(void)

for_each_cpu(cpu, frozen_cpus) {
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
- error = _cpu_up(cpu, 1);
+ error = _cpu_up(cpu);
trace_suspend_resume(TPS("CPU_ON"), cpu, false);
if (!error) {
pr_info("CPU%d is up\n", cpu);
--
2.4.3

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