Re: [PATCH] kill hotplug init/exit section annotations

From: Sam Ravnborg
Date: Thu Jan 31 2008 - 13:34:40 EST


On Thu, Jan 31, 2008 at 09:48:01AM -0800, Arjan van de Ven wrote:
> On Thu, 31 Jan 2008 19:14:36 +0200
> Adrian Bunk <bunk@xxxxxxxxxx> wrote:
> > > cpuhotplug is required for suspend/resume.
> >
> > Not on UP computers.
> >
>
> great! someone who still has one of those and uses a kernel without it.
> Can you look at your system.map and see how many kilobytes you've gained?
> Eg how many kilobytes are in these sections exactly?
I have one. A Atmel AT91 board equipped with an 9263.
So lets take a look at the defconfig build for the evaluation board.


o-arm/vmlinux.o: file format elf32-littlearm

0 .text 001cdefc 00000000 00000000 00000400 2**10
2 .init.text 000165e8 00000000 00000000 001ce6c0 2**5
26 .init.data 000032ec 00000000 00000000 002578cc 2**2

---

4 .devinit.text 00001558 00000000 00000000 001e5270 2**2
9 .exit.text 00000bc8 00000000 00000000 001e8d2c 2**2
10 .cpuinit.text 00000924 00000000 00000000 001e98f4 2**2
11 .meminit.text 000004cc 00000000 00000000 001ea218 2**2
12 .devexit.text 00000160 00000000 00000000 001ea6e4 2**2
38 .cpuinit.data 00000040 00000000 00000000 0025afc0 2**2
39 .meminit.data 0000000c 00000000 00000000 0025b000 2**2


__devinit alone gives a net win of 5464 bytes.
That is only ~3% of total .text size but this is non-swapable
memory where everything is worth it.
And the configuration selected is by no means optimal
with respect to minimal size.

Sam
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