Messages in this thread | | | Subject | Re: [PATCH 2/3][RFC] tracing: Add optional percpu buffers for trace_printk() | From | Steven Rostedt <> | Date | Mon, 10 Oct 2011 09:17:05 -0400 |
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On Mon, 2011-10-10 at 15:04 +0200, Peter Zijlstra wrote: > 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.
Hmm, I could do that. Of course this will add a check for a global variable in all trace_printks. I could make it a read_mostly variable, as it only gets updated once, or even encapsulate the entire check with a static_switch() :)
> > > 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 :-)
I've had too many, I'm not sure my head could take much more.
-- Steve
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