Re: recursion handling: Re: [PATCH next v2 3/3] printk: remove logbuf_lock, add syslog_lock

[Sergey Senozhatsky]

On (20/12/04 17:10), Petr Mladek wrote:
> 
> One reason is the use of per-cpu variables. Alternative solution would
> be to store printk_context into task_struct.

We can keep per-CPU, disable preemption and have counters for
every context (task, soft/hard irq, NMI). Shouldn't be a problem

	vprintk_emit()
	{
		preempt_disable()
		vprintk_store()
		preempt_enable()

		preempt_disable()
		console_unlock()
		preempt_enable()
	}

vprintk_store() is a small fraction of console_unlock() time wise.

	-ss