Re: [PATCH 2/3][RFC] tracing: Add optional percpu buffers fortrace_printk()

From: Peter Zijlstra
Date: Mon Oct 10 2011 - 08:58:30 EST


On Mon, 2011-10-10 at 08:37 -0400, Steven Rostedt wrote:

> This will make debugging some of my embedded boards difficult (the ones
> where I have no way to add kernel command lines). If there's a problem
> at boot up, I will have to modify the kernel to get this to print.
>
> For those that don't know the tracing code, it will just simply break.
>
> Unless you want me to keep the kconfig option that enables it
> permanently. Then I could do this.

There's a fairly easy fix for that, initialize it at boot, and free once
userspace it up and running if no trace_printk() came by.

> I also expect tglx to throw frozen sharks at me for "why doesn't
> trace_printk() work anymore?!!!!"

I'm sure you'll get over that :-)

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