show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used.
Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, I have a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level than the backtrace). Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Jann Horn <ja...@google.com> Cc: Petr Mladek <pmla...@suse.com> Cc: Sergey Senozhatsky <sergey.senozhat...@gmail.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> Cc: Thomas Gleixner <t...@linutronix.de> Cc: x...@kernel.org [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-d...@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-d...@arista.com/ Dmitry Safonov (3): x86/dumpstack: Add log_lvl to show_iret_regs() x86/dumpstack: Add log_lvl to __show_regs() x86/dumpstack: Show registers dump with trace's log level arch/x86/include/asm/kdebug.h | 5 ++-- arch/x86/kernel/dumpstack.c | 23 +++++++++------- arch/x86/kernel/process_32.c | 29 ++++++++++---------- arch/x86/kernel/process_64.c | 51 ++++++++++++++++++----------------- 4 files changed, 57 insertions(+), 51 deletions(-) -- 2.27.0