The following commit has been merged into the sched/core branch of tip:
Commit-ID: 15faafc6b449777a85c0cf82dd8286c293fed4eb
Gitweb: https://git.kernel.org/tip/15faafc6b449777a85c0cf82dd8286c293fed4eb
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 31 May 2021 12:21:13 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 01 Jun 2021 16:00:11 +02:00
sched,init: Fix DEBUG_PREEMPT vs early boot
Extend 8fb12156b8db ("init: Pin init task to the boot CPU, initially")
to cover the new PF_NO_SETAFFINITY requirement.
While there, move wait_for_completion(&kthreadd_done) into kernel_init()
to make it absolutely clear it is the very first thing done by the init
thread.
Fixes: 570a752b7a9b ("lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Tested-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Tested-by: Borislav Petkov <bp@xxxxxxxxx>
Link: https://lkml.kernel.org/r/YLS4mbKUrA3Gnb4t@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
init/main.c | 11 ++++++-----
kernel/sched/core.c | 1 +
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/init/main.c b/init/main.c
index 7b027d9..e945ec8 100644
--- a/init/main.c
+++ b/init/main.c
@@ -692,6 +692,7 @@ noinline void __ref rest_init(void)
*/
rcu_read_lock();
tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+ tsk->flags |= PF_NO_SETAFFINITY;
set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
rcu_read_unlock();
@@ -1440,6 +1441,11 @@ static int __ref kernel_init(void *unused)
{
int ret;
+ /*
+ * Wait until kthreadd is all set-up.
+ */
+ wait_for_completion(&kthreadd_done);
+
kernel_init_freeable();
/* need to finish all async __init code before freeing the memory */
async_synchronize_full();
@@ -1520,11 +1526,6 @@ void __init console_on_rootfs(void)
static noinline void __init kernel_init_freeable(void)
{
- /*
- * Wait until kthreadd is all set-up.
- */
- wait_for_completion(&kthreadd_done);
-
/* Now the scheduler is fully set up and can do blocking allocations */
gfp_allowed_mask = __GFP_BITS_MASK;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3d25272..e205c19 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8862,6 +8862,7 @@ void __init sched_init_smp(void)
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0)
BUG();
+ current->flags &= ~PF_NO_SETAFFINITY;
sched_init_granularity();
init_sched_rt_class();
|