Re: x86: Why have __copy_from_user_ll_nocache* been exported?

From: Ingo Molnar
Date: Thu Jan 31 2008 - 15:32:01 EST



* Adrian Bunk <bunk@xxxxxxxxxx> wrote:

> A commit that does nothing except for adding two unused
> EXPORT_SYMBOL's.
>
> Without any rationale why they should be exported.

the rationale is obvious: it's part of the standard uaccess
functionality and while it's rarely used (in fact it's not used by any
modular code right now) there's no reason not to export it alongside the
other uaccess vectors. We can unexport it once we unexport all uses of
the uaccess APIs. We could make it a _GPL export perhaps.

It's very annoying to driver writers when a small portion of a sensible
API vector is not available symmetrically.

> And that from a person who on the other hand wants to introduce (and
> tries to force on other people) deprecation periods for unused
> EXPORT_SYMBOL's.

why does this bother you? The API makes total sense. This is a
completely sensible API (with a full implementation) to use non-temporal
copies. I mean, if this was some legacy API that nobody uses anymore i'd
agree, but this is about the ability to access user-space memory via
SSE2+ non-temporal stores.

Ingo
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