Re: [tip:x86/cleanups] x86: Remove pr_fmt duplicate logging prefixes

From: Bjorn Helgaas
Date: Thu Feb 21 2019 - 01:25:58 EST


On Thu, May 17, 2018 at 11:45 AM Joe Perches <joe@xxxxxxxxxxx> wrote:
>
> On Thu, 2018-05-17 at 20:27 +0200, Borislav Petkov wrote:
> > On Sun, May 13, 2018 at 12:27:45PM -0700, tip-bot for Joe Perches wrote:
> > > Commit-ID: 1de392f5d5e803663abbd8ed084233f154152bcd
> > > Gitweb: https://git.kernel.org/tip/1de392f5d5e803663abbd8ed084233f154152bcd
> > > Author: Joe Perches <joe@xxxxxxxxxxx>
> > > AuthorDate: Thu, 10 May 2018 08:45:30 -0700
> > > Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > > CommitDate: Sun, 13 May 2018 21:25:18 +0200
> > >
> > > x86: Remove pr_fmt duplicate logging prefixes
> > >
> > > Converting pr_fmt from a default simple #define to use KBUILD_MODNAME
> > > added some duplicate prefixes.
> > >
> > > Remove the duplicate prefixes.
> []
> > Maybe I'm missing something but this dropped the prefixes now
> > completely:
> >
> > -e820: BIOS-provided physical RAM map:
> > +BIOS-provided physical RAM map:
> >
> > -e820: last_pfn = 0x43f000 max_arch_pfn = 0x400000000
> > +last_pfn = 0x43f000 max_arch_pfn = 0x400000000
> >
> > -e820: last_pfn = 0x9d000 max_arch_pfn = 0x400000000
> > +last_pfn = 0x9d000 max_arch_pfn = 0x400000000
> >
> > ...
> >
> > I don't think that was the intention.
>
> Hi Borislav
>
> It wasn't and isn't the intention.
>
> This is a patch _series_, and all of the patches
> from 4-18 depend on patch 3 which converts the
> generic define in include/linux/printk.h
>
> from
> #define pr_fmt(fmt) fmt
> to
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> Perhaps a better option, which could be done in
> a v2 of the series, is to add a temporary
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> to each file modified in patches 4-18 and then
> allow the follow-on script described in the 0/18
> cover letter to remove those #defines

Was there ever a v2? What I see from 1de392f5d5e8 ("x86: Remove
pr_fmt duplicate logging prefixes") is exactly what Borislav noted.

For example, https://bugzilla.kernel.org/attachment.cgi?id=281007 is a
v4.20 dmesg log from
https://bugzilla.kernel.org/show_bug.cgi?id=202511 . That bug also
has a v4.17 dmesg log
(https://bugzilla.kernel.org/attachment.cgi?id=281011). Comparing
them shows:

-Linux version 4.17.19-gentoo (root@survivor) (gcc version 7.3.0
(Gentoo 7.3.0-r3 p1.4)) #2 SMP Sat Sep 22 09:53:01 EDT 2018
+Linux version 4.20.6-gentoo (root@survivor) (gcc version 7.3.0
(Gentoo 7.3.0-r3 p1.4)) #1 SMP Tue Feb 5 09:46:51 EST 2019
...
-e820: BIOS-provided physical RAM map:
+BIOS-provided physical RAM map:

Not a big deal as far as I'm concerned, but it is a minor annoyance.

Bjorn