On Thu, 23 Jul 2020 12:57:35 +0200 Vincent Whitchurch <[email protected]> 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. -- Steve
