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

[Wilson Li]

--- "linux-os (Dick Johnson)" <linux-os@xxxxxxxxxxxx> wrote:

> 
> On Wed, 28 Sep 2005, 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 don't think it's a problem with the size. Here is the
> `lspci` output after I hacked a Rtc module to use 16 megabytes
> of data space. It took about 1/4 second to load (`time insmod
> Rtc.ko`).
> 
> Module                  Size  Used by
> Rtc                 16783748  0
> floppy                 58964  0
> loop                   18440  0
> parport_pc             28740  1
> lp                     14472  0
> parport                37320  2 parport_pc,lp
> 
> [SNIPPED...]
> 
> 
> > Initially I suspected there might be a problem of the insmod of
> > busybox I was using. I switched to module-init-tools-3.1 insmod.
> It
> > didn't help. I also tried other things like disabling
> CONFIG_KALLSYMS
> > and commenting out all the EXPORT_SYMBOLs in that module. Nothing
> > works so far. I've not been able to find any relevant thread
> about
> > slow loading of big kernel module on PPC platform.
> >
> 
> The PPC might be a bit slower, but not as slow as you are
> seeing. I suspect that you have something that is 'waiting'
> for initialization.

For debugging, my module init function will print a message first
when it gets called. After insmod the module, the console hangs about
90 seconds for loading then my init function gets called and message
prints. I even commented out all the initialization code, it still
does not help. Anything else I am missing?

Thanks,
Wilson Li


	
		
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