[RFC] shipping kernels with default modules?

[Kostik Belousov]

On Sat, Jun 11, 2011 at 02:00:20PM -0600, Warner Losh wrote:
> 
> On Jun 11, 2011, at 12:34 PM, Doug Barton wrote:
> > On 6/11/2011 2:21 AM, Adrian Chadd wrote:
> >> Hi guys,
> >> 
> >> Has there been any further thought as of late about shipping kernels
> >> with modules only by default, rather than monolithic kernels?
> >> 
> >> I tried this experiment a couple years ago and besides a little
> >> trickery with ACPI module loading, it worked out fine.
> >> 
> >> Is there any reason we aren't doing this at the moment? Eg by having a
> >> default loader modules list populated from the kernel config file?
> > 
> > Has anyone benchmarked monolithic vs. modular? I think that should be done before we move in this direction.
> 
> I haven't noticed a difference, but I haven't done any specific benchmarking.

There might be some measurable difference on i386, where we use dso for
modules. As a consequence, the overhead of GOT/PLT indirection, and, more
important, stolen %ebx on the register-starved architecture, may make
a difference. I doubt that any difference can be measured on amd64.
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