On Mon 2022-02-14 11:13:09, Guilherme G. Piccoli wrote: > The panic_print setting allows users to collect more information in a > panic event, like memory stats, tasks, CPUs backtraces, etc. > This is an interesting debug mechanism, but currently the print event > happens *after* kmsg_dump(), meaning that pstore, for example, cannot > collect a dmesg with the panic_print extra information. > > This patch changes that in 2 steps: > > (a) The panic_print setting allows to replay the existing kernel log > buffer to the console (bit 5), besides the extra information dump. > This functionality makes sense only at the end of the panic() function. > So, we hereby allow to distinguish the two situations by a new boolean > parameter in the function panic_print_sys_info(). > > (b) With the above change, we can safely call panic_print_sys_info() > before kmsg_dump(), allowing to dump the extra information when using > pstore or other kmsg dumpers. > > The additional messages from panic_print could overwrite the oldest > messages when the buffer is full. The only reasonable solution is to > use a large enough log buffer, hence we added an advice into the kernel > parameters documentation about that. > > Cc: Feng Tang <feng.tang@xxxxxxxxx> > Cc: Petr Mladek <pmladek@xxxxxxxx> > Acked-by: Baoquan He <bhe@xxxxxxxxxx> > Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> Makes sense and looks good to me. Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Best Regards, Petr _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
