Re: [PATCH 407/493] infiniband: remove use of __devexit

Jason Gunthorpe
2012-11-19T21:49:22Z

On Mon, Nov 19, 2012 at 12:19:38PM -0800, Greg KH wrote:
> On Mon, Nov 19, 2012 at 01:09:21PM -0700, Jason Gunthorpe wrote:
> > On Mon, Nov 19, 2012 at 01:25:56PM -0500, Bill Pemberton wrote:
> > > CONFIG_HOTPLUG is going away as an option so __devexit is no
> > > longer needed.
> >
> > I'm sad to hear this, it is an easy space saver on my non-modular
> > emebedded systems :(
>
> Really? I asked for details, and it was reported that this only saved
> 1-200 bytes or so. See the lkml archives for the details of this.

I just checked for you:

Old 2.6.16 powerpc 32 kernel:

text data bss dec hex filename
2399368 222224 156124 2777716 2a6274 build/vmlinux
2394634 221804 156124 2772562 2a4e52 build-nhp/vmlinux

That looks like around 5154 bytes to me

New 3.6 powerpc 32 kernel:

text data bss dec hex filename
3352356 162812 218132 3733300 38f734 build/vmlinux
3347644 162648 217860 3728152 38e318 build-nhp/vmlinux

And that is about 5148 bytes.

In both cases the only difference is adding CONFIG_HOTPLUG=y to the
config.

5k isn't a lot, but in the context of 'I have to figure out how to
trim ~1MB off the 3.6 kernel to run it in our smallest hardware' it is
the wrong direction :(

Regards,
Jason