Messages in this thread | | | From | "Guilherme G. Piccoli" <> | Subject | About ftrace+pstore+ramoops | Date | Thu, 26 Nov 2020 18:33:09 -0300 |
| |
Hi Anton / Joel (and all CCed), sorry for annoyance but I'm not being able to make pstore ftrace capture to work - I'm not sure if I might be missing something, or if there's a known limitation.
So, first, my use case: I'd like to be able to collect *ftrace* trace buffer in a specific point in time, when some issue I'm facing happens; for that, I enable ftrace through tracing_on() in the correct point in the code. After this issue, machine is not responsive, so I need to reboot (hence I'd like to persist the trace buffer in my ramoops reserved area).
For the basic test purpose though, I'm doing just what is suggested in the ramoops documentation, which is to write 1 on <debugfs>/pstore/record_ftrace and reboot - but no ftrace file is present in the pstore folder after the reboot. I've tested the same system/config by inducing a kernel oops and the corresponding dmesg-ramoops file is there after the reboot...
Just for clarification: this ftrace feature in pstore is meant to do what I want right? It should *always* collect the same information as seen in the trace buffer, but on the persistent memory region configured by ramoops, correct? Any guidance you can provide me is much appreciated. Thanks in advance,
Guilherme
| |