The section on the 'debug' parameter refers the user to <linux/kernel.h> for more information on kernel log levels, however, that file contains neither a description of console_loglevel nor nor a description of the various log levels. The closest I can find is <include/linux/kern_levels.h>, which defines the various log levels but doesn't explain console_loglevel, Also, it only exists in recent kernels, version 3.5 and up. Another candidate would be <include/linux/printk.h>, which does define console_loglevel but doesn't explain the individual log levels. Perhaps both references (<include/linux/printk.h>, <include/linux/kern_levels.h>) could be included? Kind regards, Alain
Found in Arch Linux, package man-pages 3.83-1. Confirmed in http://man7.org/linux/man-pages/man7/bootparam.7.html
Hello Alain and Michael, We can quote every level rather than refer to two files. What do you think about, Michael? Regards, -- Stéphane Aulery
(In reply to Alain Kalker from comment #0) > The section on the 'debug' parameter refers the user to <linux/kernel.h> for > more information on kernel log levels, however, that file contains neither a > description of console_loglevel nor nor a description of the various log > levels. > > The closest I can find is <include/linux/kern_levels.h>, which defines the > various log levels but doesn't explain console_loglevel, Also, it only > exists in recent kernels, version 3.5 and up. > Another candidate would be <include/linux/printk.h>, which does define > console_loglevel but doesn't explain the individual log levels. > > Perhaps both references (<include/linux/printk.h>, > <include/linux/kern_levels.h>) could be included? Hello Alain, I must say I'm generally quite unhappy with the sate of the bootparam(7) page. I'm actually not sure that it was ever a good idea to create it to begin with. But that happened 20 years ago, well before my time as maintainer. As it is now, the page is *horribly( dated, and your report made me seriously think of just removing the page! As it is, I have settled for discarding 60% of the page, and fixing a few of the more glaring errors in the remainder. Regarding your report, I amended the test on 'debug' to read: Boot arguments for use by kernel developers 'debug' Kernel messages are handed off to a daemon (e.g., klogd(8) or similar) so that they may be logged to disk. Messages with a priority above console_loglevel are also printed on the console. (For a discussion of these lev‐ els, see syslog(2).) By default, console_loglevel is set to log messages at levels higher than KERN_DEBUG. This boot argument will cause the kernel to also print messages logged at level KERN_DEBUG. The console loglevel can also be set on a booted system via the /proc/sys/kernel/printk file (described in syslog(2)), the syslog(2) SYSLOG_ACTION_CONSOLE_LEVEL operation, or dmesg(8). I believe that should address your concerns, so I'm closing the bug. Cheers, Michael