The following commit has been merged into the smp/core branch of tip:
Commit-ID: d308077e5e4dc8c93f97f5ebc70274e7c7a92d49
Gitweb: https://git.kernel.org/tip/d308077e5e4dc8c93f97f5ebc70274e7c7a92d49
Author: Steven Price <steven.price@xxxxxxx>
AuthorDate: Mon, 11 Apr 2022 16:22:33 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 13 Apr 2022 21:27:41 +02:00
cpu/hotplug: Initialise all cpuhp_cpu_state structs earlier
Rather than waiting until a CPU is first brought online, do the
initialisation of the cpuhp_cpu_state structure for each CPU during the
__init phase. This saves a (small) amount of non-__init memory and
avoids potential confusion about when the cpuhp_cpu_state struct is
valid.
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220411152233.474129-3-steven.price@xxxxxxx
---
kernel/cpu.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index d0a9aa0..02a77ac 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -716,14 +716,6 @@ static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
/*
* The cpu hotplug threads manage the bringup and teardown of the cpus
*/
-static void cpuhp_create(unsigned int cpu)
-{
- struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
-
- init_completion(&st->done_up);
- init_completion(&st->done_down);
-}
-
static int cpuhp_should_run(unsigned int cpu)
{
struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
@@ -883,15 +875,27 @@ static int cpuhp_kick_ap_work(unsigned int cpu)
static struct smp_hotplug_thread cpuhp_threads = {
.store = &cpuhp_state.thread,
- .create = &cpuhp_create,
.thread_should_run = cpuhp_should_run,
.thread_fn = cpuhp_thread_fun,
.thread_comm = "cpuhp/%u",
.selfparking = true,
};
+static __init void cpuhp_init_state(void)
+{
+ struct cpuhp_cpu_state *st;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ st = per_cpu_ptr(&cpuhp_state, cpu);
+ init_completion(&st->done_up);
+ init_completion(&st->done_down);
+ }
+}
+
void __init cpuhp_threads_init(void)
{
+ cpuhp_init_state();
BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads));
kthread_unpark(this_cpu_read(cpuhp_state.thread));
}
|