Re: [PATCH] x86: fix improper .init-type section references

From: Sam Ravnborg
Date: Wed Jun 13 2007 - 04:10:01 EST


On Wed, Jun 13, 2007 at 01:09:07PM +0530, Satyam Sharma wrote:
>
> i.e. don't discard anything at build time, and link the .exit.{text,
> data} sections
> into the kernel image for _all_ archs? (otherwise how do we avoid
> special-casing/
> checking for the arch in modpost and warn/not-warn about invalid/valid
> cases)
>
> But then why not simply lose the __exit (and .exit.*) altogether? Because
> __exit becomes redundant in the suggested changed semantics -- just mark
> all the cleanup code as __init too (when it's built-in, the only
> callsite for the
> cleanup code would be from the startup code in .init.*, and when modular,
> __init and __exit lose all relevance anyway).

The reason we do it today is to save memory in a memory constrained environment.
So with such a suggestion you should back it up with numbers.

How much RAM is wasted by keeping the __init and _exit sections
in memory for a normal embedded build?

You could try a random defconfig for arm or mips since they are
embedded in general. Using defconfig for i386 could tell us
a little but not that important.

And when evaluating the numbers think of maybe 8 MB RAM in total, no swap
storage, and sloow filesystem for permanent storage.

Sam
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