Re: Slow loading big kernel module in 2.6 on PPC platform

[Wilson Li <yongshenglee@yahoo.com>]

--- Samuel Masham <Samuel.Masham@jp.sony.com> wrote:

> > Wilson Li wrote:
> > > Hi,
> > > 
> > > I am trying to port several third party kernel modules from
> > kernel
> > > 2.4 to 2.6 on a ppc (MPC824x) platform. For small size of
> > modules, it
> > > works perfectly in 2.6. But there's one huge kernel module
> which
> > size
> > > is about 2.7M bytes (size reported by lsmod after insmod), and
> it
> > > takes about 90 seconds to load this module before init_module
> > starts.
> > > I did not notice there's such obvious delay in 2.4 kernel.
> 
> I assume you are on a slow ppc32 platform.
> 
> The time taken is a function of the number of symbols, you can work
> around it 
> as shown in the patch below. Obviously this is just an example
> patch and is
> NOT signed off for anything but reading :)
> 
> I would really like do some work on a pre-link for modules but
> don't really know 
> where to start.
> 
> Any hints?
> 
> Samuel
> 
> ps Not subscribed, just  so please cc me
> 

Here's my two cents.

1. Add time-consuming get_plt_size() functionality to
scripts/mod/modpost.c (per arch), and calculate the size when
scripts/mod/modpost is called to generate mymodule.mod.c during
making of kernel module.

2. How to pass this info down to sys_init_module() in kernel? Maybe
we can add a special section in mymodule.mod.c. So this info will be
part of mymodule.ko and parsed by sys_init_module() later.

Then it won't make too much impact on the build process.

Sounds easy;-) Hopefully it'll work.

Wilson Li







	
		
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