On 2024-06-25, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > You may be interested in some work I'm doing that allows you to read > the ring buffer from a previous kernel after a crash. > > https://lore.kernel.org/linux-trace-kernel/20240612231934.608252486@xxxxxxxxxxx/ > > I also have a way to ask for any memory, that should be able to get the > same location most times, via a "reserve_mem=" kernel command line > parameter. > > https://lore.kernel.org/linux-trace-kernel/20240613233415.734483785@xxxxxxxxxxx/ > > They are both destined for the next merge window. After that, I have > one more patch that ties the two together, so that you can have a > kernel command line of: > > reserve_mem=12M:4096:trace trace_instance=bootmap@trace > > and then when you boot up, you would have a trace instance that would > be mapped to that memory. If your machine doesn't clear memory after a > crash, you can read the data from the crash on the next boot. Nice. Thanks for the heads up. It will be nice to implement a "printk" label as well. ;-) John Ogness
