Messages in this thread | | | Date | Fri, 14 Aug 2020 15:34:15 +0200 | From | Vincent Whitchurch <> | Subject | Re: [PATCH] dynamic debug: allow printing to trace event |
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On Thu, Jul 23, 2020 at 05:26:44PM +0200, Steven Rostedt wrote: > On Thu, 23 Jul 2020 12:57:35 +0200 > Vincent Whitchurch <vincent.whitchurch@axis.com> wrote: > > > Would it be acceptable to just use a fixed size for the event? At least > > for my own debugging use cases it's preferable to just have to increase > > the trace buffer size in case it's insufficient, rather than to have to > > restort to one-off debugging code. > > There's two other options. > > Option 1, is to allocate 256 bytes times 4 (in case of interruption, > where you have a separate buffer for every context - normal, softirq, > irq, nmi), and use it like I do for stack traces in the latest kernel > (see __ftrace_stack_trace() in kernel/trace/trace.c) > > Option 2, would be to use trace_array_vprintk(), but you need to create > your own instance to do so to keep from messing with the top level buffer.
Thanks for the suggestions, I've sent out a v2 implementing option 1:
https://lore.kernel.org/lkml/20200814133151.7759-1-vincent.whitchurch@axis.com/
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