Messages in this thread | | | Subject | Re: [PATCH 2/3][RFC] tracing: Add optional percpu buffers for trace_printk() | From | Peter Zijlstra <> | Date | Mon, 10 Oct 2011 13:08:33 +0200 |
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On Sat, 2011-10-08 at 13:02 -0400, Steven Rostedt wrote: > > Ideally, using percpu buffers would be useful, but since trace_printk() > is only used in development, having per cpu buffers for something > never used is a waste of space. We could make this a compile option > but trace_printk() may also be used for developing modules, on a > distro kernels or for debugging at customer sites. > > The approach taken here is to dynamically allocate percpu buffers > with a new tracing/options switch "trace_printk_percpu". It can > be allocated and freed at runtime, or "trace_printk_percpu" may also > be specified on the command line and it will be allocated at boot up. > > This allows a developer to create percpu buffers for trace_printk() > on a running system, and also free them when not in used.
Kill the old code, make tracing/events/trace_printk default to 0 and use enabling of that to allocate your per-cpu buffers.
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