Re: [RFC][PATCH 4/4] printk: enable printk offloading

From: Petr Mladek
Date: Wed Mar 22 2017 - 11:43:36 EST


On Mon 2017-03-06 21:45:54, Sergey Senozhatsky wrote:
> Initialize the kernel printing thread and enable printk()
> offloading.

The patch looks fine to me. But it might get more complicated
if we decide to have a global option to avoid the kthread.
Let's discuss this in the 3rd patch first.

Best Regards,
Petr

> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> ---
> kernel/printk/printk.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index 6e00073a7331..601a9ef6db89 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -2779,6 +2779,25 @@ static int printk_kthread_func(void *data)
> return 0;
> }
>
> +/*
> + * Init printk kthread at late_initcall stage, after core/arch/device/etc.
> + * initialization.
> + */
> +static int __init init_printk_kthread(void)
> +{
> + struct task_struct *thread;
> +
> + thread = kthread_run(printk_kthread_func, NULL, "printk");
> + if (IS_ERR(thread)) {
> + pr_err("printk: unable to create printing thread\n");
> + return PTR_ERR(thread);
> + }
> +
> + printk_kthread = thread;
> + return 0;
> +}
> +late_initcall(init_printk_kthread);
> +
> void wake_up_klogd(void)
> {
> preempt_disable();
> --
> 2.12.0
>