Re: [PATCH] Force UNIX domain sockets to be built in

From: Adrian Bunk
Date: Mon Dec 31 2007 - 13:05:48 EST


On Mon, Dec 31, 2007 at 04:19:23PM +0100, Bodo Eggert wrote:
> On Mon, 31 Dec 2007, Adrian Bunk wrote:
> > On Mon, Dec 31, 2007 at 02:26:42PM +0100, Bodo Eggert wrote:
> > > On Mon, 31 Dec 2007, Adrian Bunk wrote:
> > > > On Mon, Dec 31, 2007 at 01:09:43PM +0100, Bodo Eggert wrote:
>
> > > > > As suggested by Adrian Bunk, UNIX domain sockets should always be built in
> > > > > on normal systems. This is especially true since udev needs these sockets
> > > > > and fails to run if UNIX=m.
> > > > >
> > > > > Signed-Off-By: Bodo Eggert <7eggert@xxxxxx>
> > > > >
> > > > > ---
> > > > > Last minute change: I decided against making it a bool because embedded
> > > > > folks might depend on a small kernel image. Edited in the patch below.
> > > > >...
> > > >
> > > > Is this just a purely theoretical thought or is this a reasonable use
> > > > case people actually use in practice?
> > >
> > > For now, it's a theoretical thought, but having an embedded device, I can
> > > see the reason for $EVERYTHING=m there.
> >
> > The only advantage I see is that the kernel image you have to flash
> > can be made smaller - with the disadvantage that the running kernel
> > is bigger by more than 10%.
> >
> > If you don't believe me, try it yourself:
> > Build all drivers statically into your kernel, and then compare the
> > vmlinux sizes with CONFIG_MODULES=n and CONFIG_MODULES=y.
>
> If you'd aim for a small kernel image, you would build anything as a module
> that is not requred for booting.
>...

Small kernel image to flash (e.g. due to a size limit there), if you
would aim for a small running kernel you wouldn't use modules.

And I'm not so sure about the image size without seeing actual numbers,
e.g. for your device.

Especially comparing your all-modular approach with a CONFIG_MODULES=n
kernel using Denys' section garbage collection patches in both cases
would be interesting.

I'm not claiming you are wrong, all I say is that I'm not convinced
without actual numbers that you are right.

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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