Commit-ID: ba997462435f48ad1501320e9da8770fd40c59b1
Gitweb: http://git.kernel.org/tip/ba997462435f48ad1501320e9da8770fd40c59b1
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Fri, 26 Feb 2016 18:43:24 +0000
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 1 Mar 2016 20:36:53 +0100
cpu/hotplug: Restructure cpu_up code
Split out into separate functions, so we can convert it to a state machine.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Rafael Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: "Srivatsa S. Bhat" <srivatsa@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Sebastian Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20160226182340.429389195@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/cpu.c | 69 +++++++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 47 insertions(+), 22 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 41a6cb8..15a4136 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -228,6 +228,43 @@ static int cpu_notify(unsigned long val, unsigned int cpu)
return __cpu_notify(val, cpu, -1, NULL);
}
+/* Notifier wrappers for transitioning to state machine */
+static int notify_prepare(unsigned int cpu)
+{
+ int nr_calls = 0;
+ int ret;
+
+ ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
+ if (ret) {
+ nr_calls--;
+ printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
+ __func__, cpu);
+ __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
+ }
+ return ret;
+}
+
+static int notify_online(unsigned int cpu)
+{
+ cpu_notify(CPU_ONLINE, cpu);
+ return 0;
+}
+
+static int bringup_cpu(unsigned int cpu)
+{
+ struct task_struct *idle = idle_thread_get(cpu);
+ int ret;
+
+ /* Arch-specific enabling code. */
+ ret = __cpu_up(cpu, idle);
+ if (ret) {
+ cpu_notify(CPU_UP_CANCELED, cpu);
+ return ret;
+ }
+ BUG_ON(!cpu_online(cpu));
+ return 0;
+}
+
#ifdef CONFIG_HOTPLUG_CPU
static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
@@ -481,7 +518,7 @@ void smpboot_thread_init(void)
static int _cpu_up(unsigned int cpu, int tasks_frozen)
{
struct task_struct *idle;
- int ret, nr_calls = 0;
+ int ret;
cpu_hotplug_begin();
@@ -496,33 +533,21 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
goto out;
}
+ cpuhp_tasks_frozen = tasks_frozen;
+
ret = smpboot_create_threads(cpu);
if (ret)
goto out;
- cpuhp_tasks_frozen = tasks_frozen;
-
- ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
- if (ret) {
- nr_calls--;
- pr_warn("%s: attempt to bring up CPU %u failed\n",
- __func__, cpu);
- goto out_notify;
- }
-
- /* Arch-specific enabling code. */
- ret = __cpu_up(cpu, idle);
-
- if (ret != 0)
- goto out_notify;
- BUG_ON(!cpu_online(cpu));
+ ret = notify_prepare(cpu);
+ if (ret)
+ goto out;
- /* Now call notifier in preparation. */
- cpu_notify(CPU_ONLINE, cpu);
+ ret = bringup_cpu(cpu);
+ if (ret)
+ goto out;
-out_notify:
- if (ret != 0)
- __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
+ notify_online(cpu);
out:
cpu_hotplug_done();
--
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