[PATCH] kthread: Use TASK_IDLE state for newly created kernel threads

From: Pavankumar Kondeti
Date: Wed May 20 2020 - 07:55:38 EST


When kernel threads are created for later use, they will be in
TASK_UNINTERRUPTIBLE state until they are woken up. This results
in increased loadavg and false hung task reports. To fix this,
use TASK_IDLE state instead of TASK_UNINTERRUPTIBLE when
a kernel thread schedules out for the first time.

Signed-off-by: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
---
kernel/kthread.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index bfbfa48..b74ed8e 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -250,7 +250,7 @@ static int kthread(void *_create)
current->vfork_done = &self->exited;

/* OK, tell user we're spawned, wait for stop or wakeup */
- __set_current_state(TASK_UNINTERRUPTIBLE);
+ __set_current_state(TASK_IDLE);
create->result = current;
/*
* Thread is going to call schedule(), do not preempt it,
@@ -428,7 +428,7 @@ static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state)

void kthread_bind_mask(struct task_struct *p, const struct cpumask *mask)
{
- __kthread_bind_mask(p, mask, TASK_UNINTERRUPTIBLE);
+ __kthread_bind_mask(p, mask, TASK_IDLE);
}

/**
@@ -442,7 +442,7 @@ void kthread_bind_mask(struct task_struct *p, const struct cpumask *mask)
*/
void kthread_bind(struct task_struct *p, unsigned int cpu)
{
- __kthread_bind(p, cpu, TASK_UNINTERRUPTIBLE);
+ __kthread_bind(p, cpu, TASK_IDLE);
}
EXPORT_SYMBOL(kthread_bind);

--
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