Re: rfc: remove early_printk from a few arches? (blackfin, m68k, mips)

From: Måns Rullgård
Date: Fri Dec 19 2014 - 05:33:57 EST


Joe Perches <joe@xxxxxxxxxxx> 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@xxxxxxxxx
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