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SubjectRe: Portable binary modules
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> Not at the binary level. Our uniprocessor builds make most
> spinlocks become null code or local cli/sti instructions. That
> avoids us taking the performance hit. It also means that the locks
> the SMP module wants to use are not actually there in truth.

Every single problem that has been mentioned about Binary Portable
modules for the Linux kernel is solvable. For the case of SMP and UP
kernel modules, allow the developer the *option* of compiling the
binary module with or withour SMP support. If compiled with SMP
support, the module should still work on a UP kernel as the kernel
would provide dummy locking functions or the UP equivalents to the
driver. If compiled without SMP, the module would fail to load on SMP
kernels (with an error message to the system log).

In many cases binary modules could easily be built as SMP compatible
without any real performance hit on the system. If there is a
performance hit, the developer can build both SMP and UP versions of
the modules.

Regards,

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