Messages in this thread | | | Date | Wed, 13 Apr 2022 14:39:53 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH] printk/index: Printk index feature documentation |
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On Tue 2022-04-05 13:22:49, Chris Down wrote: > Petr Mladek writes: > > Document the printk index feature. The primary motivation is to > > explain that it is not creating KABI from particular printk() calls. > > > > Signed-off-by: Petr Mladek <pmladek@suse.com> > > Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> > > This looks great, thanks a lot for spending the time to write this up. Just > some very minor comments.
Ah, I forgot to do the small fixup when pushing. So, I did it now are rebased.
> > --- /dev/null > > +++ b/Documentation/core-api/printk-index.rst > > +User Interface > > +============== > > + > > +The index of printk formats are split in into separate files. The files are > > +named according to the binaries where the printk formats are built-in. There > > +is always "vmlinux" and optionally also modules, for example:: > > + > > + /sys/kernel/debug/printk/index/vmlinux > > + /sys/kernel/debug/printk/index/ext4 > > + /sys/kernel/debug/printk/index/scsi_mod > > + > > +Note that only loaded modules are shown. Also printk formats from a module > > +might appear in "vmlinux" when the module is built-in. > > + > > +The content is inspired by the dynamic debug interface and looks like:: > > s/::/:/
The double double dots '::' cause that the following paragraph will be block quoting. There is only single ':' in the generated html.
> > + $> head -1 /sys/kernel/debug/printk/index/vmlinux; shuf -n 5 vmlinux > > + # <level[,flags]> filename:line function "format" > > + <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n" > > + <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n" > > + <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n" > > + <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n" > > + <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n" > > + > > +, where the meaning is::
I uses only single double dot here.
> > + - level: log level > > Maybe worth noting that level may not be there if we have a KERN_CONT.
I added:
- :level: log level value: 0-7 for particular severity, -1 as default, 'c' as continuous line without an explicit log level
> > + - flags: optional flags: currently only 'c' for KERN_CONT > + - filename:line: source filename and line number of the related > > + printk() call. Note that there are many wrappers, for example, > > + pr_warn(), pr_warn_once(), dev_warn(). > > + - function: function name where the printk() call is used. > > + - format: format string
I added few more double dots to generate bold: 'level', 'flags', 'filename:line', etc.
See the updated commit at https://git.kernel.org/pub/scm/linux/kernel/git/printk/linux.git/commit/?h=for-5.19&id=a5c7a39f508ae1fd3288493b96dd26079bae41bf
Best Regards, Petr
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