linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Måns Rullgård" <mans@mansr.com>
To: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	linux-arch <linux-arch@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	linux-m68k <linux-m68k@vger.kernel.org>,
	Steven Miao <realmz6@gmail.com>,
	Ralf Baechle <ralf@linux-mips.org>,
	linux-mips <linux-mips@linux-mips.org>
Subject: Re: rfc: remove early_printk from a few arches? (blackfin, m68k, mips)
Date: Fri, 19 Dec 2014 10:33:42 +0000	[thread overview]
Message-ID: <yw1xy4q4exo9.fsf@unicorn.mansr.com> (raw)
In-Reply-To: <1418954914.25129.1.camel@perches.com> (Joe Perches's message of "Thu, 18 Dec 2014 18:08:34 -0800")

Joe Perches <joe@perches.com> writes:

> On Fri, 2014-12-19 at 01:43 +0000, Måns Rullgård wrote:
>> What exactly are you proposing to remove?
>
> Optionally compile out
> kernel/printk/printk.c:early_printk()
> even if CONFIG_EARLY_PRINTK is enabled.
>
>> I see no unused code related
>> to early printk (in any variant) under arch/mips.
>
> I think there could be yet another CONFIG option
> to specifically enable the early_printk function
> for the arches that use it.

Why bother?  On MIPS it would save 132 bytes of compiled code.

> The kernel/printk/early_printk() function seems
> used only by arm/microblaze/tile/x86.

Rather than introduce more config complexity, you could try to remove
the 7 remaining uses of early_printk().

- arch/arm/mach-socfpga
  Single early_printk("Early printk initialized\n") call serving no
  apparent purpose can probably be safely deleted.  Since there are no
  other early_printk() calls, this information seems rather useless.

- arch/microblaze, arch/tile, arch/x86
  These all do a register_console() for the early console, so regular
  printk() should work.  Moreover, x86 allows multiple early consoles,
  but calling early_printk() will only output to the last one specified.

-- 
Måns Rullgård
mans@mansr.com

  reply	other threads:[~2014-12-19 10:33 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-17 20:58 rfc: remove early_printk from a few arches? (blackfin, m68k, mips) Joe Perches
2014-12-17 21:30 ` Kevin Cernekee
2014-12-17 22:30   ` Måns Rullgård
2014-12-18 23:33 ` Thomas Gleixner
2014-12-19  1:14   ` Joe Perches
2014-12-19  1:43     ` Måns Rullgård
2014-12-19  2:08       ` Joe Perches
2014-12-19 10:33         ` Måns Rullgård [this message]
2014-12-19 22:49           ` Joe Perches
2014-12-28 18:36           ` Pavel Machek
2014-12-19  8:03 ` Geert Uytterhoeven
2014-12-28 18:33 ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=yw1xy4q4exo9.fsf@unicorn.mansr.com \
    --to=mans@mansr.com \
    --cc=geert@linux-m68k.org \
    --cc=joe@perches.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@vger.kernel.org \
    --cc=linux-mips@linux-mips.org \
    --cc=ralf@linux-mips.org \
    --cc=realmz6@gmail.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).