On Fri, Sep 04, 2020 at 05:24:38PM +0900, Changki Kim wrote: > Printk() meesages are the most basic and useful debug method. > However, additional information needs in multi-processor. > If we add messages with processor id and process name, we can find > a problem only with messages when the problem occurs with H/W IP or CPU. > This is very useful in narrowing down the scope of the problems. > > Therefore, instead of trying to help buffering, let's try to help > reconstructing messages by saving caller information as of calling > log_store() and adding it as "[$processor_id: $process_name: $thread_id]" > upon printing to consoles. > > Some examples for console output: > > [ 0.059580] [0: swapper/0: 1] CPU: All CPU(s) started at EL1i > [ 2.153157] [5: init: 1] migov: complete to probe migov > [ 7.441317] [4: init: 1] NET: Registered protocol family 39 > [ 22.793389] [5: kworker/u16:1: 184] SMP: stopping secondary CPUs > > Signed-off-by: Changki Kim <changki....@samsung.com> > --- > kernel/printk/printk.c | 20 ++++++++++++++++++-- > kernel/printk/printk_ringbuffer.h | 7 +++++++ > lib/Kconfig.debug | 16 ++++++++++++++++ > 3 files changed, 41 insertions(+), 2 deletions(-)
Isn't the CPU number already present if you want it today? Why add it again? thanks, greg k-h
