[PATCH 16/21] kernel/kexec.c: use pr_<level> and add pr_fmt(fmt)

Joe Perches joe at perches.com
Mon Oct 5 13:57:02 EDT 2009

On Mon, 2009-10-05 at 05:01 -0700, Eric W. Biederman wrote:
> Joe Perches <joe at perches.com> writes:
> > Added #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > Converted printk(KERN_<level> to pr_<level>(
> > Added KERN_ERR to allocation failure message
> I'm dense and I haven't seen the discussions.  What
> is the point of adding a prefix string where none exists
> into a bunch of printks?

Hi Eric.

There have been a few messages on lkml with little comment,
so I thought I'd get a few more by submitting some patches.

There is a [0/21] message that you might have received directly.

I believe these are some of the +/-'s of each approach:
(copy/pasted from an earlier response)


o Allows some messages to not have a prefix at all
o Prefixes can vary inside a specific compilation unit


o Consistent, smaller source code, with no typos
  for instance: acpi/apic typos were found/fixed
                kernel/power had messages without PM:
                mce used "MCE: " and "mce: " prefixes
o Compatible with KMSG_COMPONENT
o All logging messages should have a prefix so
  it could be easier to grep/categorize logs
o Future:
  - Doesn't require each compilation unit to #define pr_fmt
  - Smaller objects without duplicated prefixes
  - Extensible via some dynamic_debug like mechanism
    to hide or show modname/__func__/offset without
    significant overhead or any increase in object size
    (printk would emit the prefix via some insertion
     mechanism after "<level>")

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