Re: [PATCH V2] docs: panic: Disclaimer about console verbosity when using panic_print with pstore
Petr Mladek <[email protected]>
| Newsgroups | org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Wed 2026-08-19 15:31:30, Guilherme G. Piccoli wrote: > Users of panic_print / panic_sys_info are usually aware of the potentially > huge amount of information displayed with such options - their goal by > using them is indeed to dump more information during panic! > > What might come unnoticed at first is the impact that the console_verbose() > call on panic path has, specially in cases that users rely on pstore as > a means to collect the panic logs. Recent experience shows that dumping > all tasks in an ARM64 system (with qcom_geni tty driver) gets a 2 minute > delay on panic time due to writing such information to console. But in > that case, pstore was used, so there was no need for console printing, > and suppressing that reduced the full time to less than 0.5 second. > > The option "printk.console_no_auto_verbose" aims exactly at this use > case: avoid automatically increasing the loglevel during panic path. > So, let's officially document this to avoid users wasting their time > either on long panic printing or debugging the panic delays. > > While at it, improve the readability of the panic_print text, by > adding some line breaks. > > Suggested-by: Petr Mladek <[email protected]> > Reviewed-by: Bradley Morgan <[email protected]> > Reviewed-by: Feng Tang <[email protected]> > Signed-off-by: Guilherme G. Piccoli <[email protected]> Looks good to me: Reviewed-by: Petr Mladek <[email protected]> I am not sure if the doc team would want to take it. I am going to wait a week or so. Then I would take it via the printk tree if anyone else did not take it in the meantime. Best Regards, Petr