invalidate_page_range() for non-GPL modules

Duncan — Fri, 20 Feb 2004 04:40:31 +0000

> One might think it would not be too controversial,
> especially since that function was first created
> and submitted by...Paul McKenney.

It would seem to me, however, that the above is only one chapter of the story.
His submission could be added to the kernel, and indeed use the REST of the
kernel, because it WAS GPLed. What of the idea of "standing on the
shoulders of giants"?

Who wrote the code that HIS patch called, or the code it was inserted in the
middle of and thus depends on? Who wrote the code that THAT code
called? Etc..

It seems to me that all the callees get veto power over this as well, at least in
theory. At minimum, it would seem that the writer of the code directly called
by the patch or that the patch or segments of were introduced in the middle
of, have veto power. How far beyond that we want to take it could be
debated, as could be what the default policy, should the author of supporting
code no longer be available or refuse to take a position. but it seems to me
that at minimum, should those authors express an opinion one way or the
other, it should be honored.

(Personally, my position is that, would any of my work ever be involved..
purely for argument's sake, since I'm not likely to ever do anything more than
trivial re the kernel.. I'd be inclined to say NO, since I wouldn't have
bothered switching from a decade on proprietary-ware if I didn't believe it
was the wrong solution, and I have strong feelings about ANYTHING I do
being supportive of proprietary-ware, PERIOD. That's why tho I use
Mandrake, itself fairly strongly libre-ware supportive, I'm not a member of
Mdk Club -- a small portion of the dues of which must go to support in
SOME way the "freebie" proprietary-ware the club offers access to as one of
its benefits. I don't want ANY support of mine going to proprietary-ware.
However, as my code is NOT part of the dependency tree, here, it's not up to
me to decide whether GPL exceptions should be granted or not.)

Duncan

digging that deeply

larryr — Thu, 19 Feb 2004 23:37:17 +0000

Andrew Morton later said

Needing access to invalidate_mmap_range() is surely not an indication of a derived work. It is an indication of a need for a reliable way to achieve inter-node cache consistency.

I agree 100%. I think any (viz non-GPL) filesystem implementation should be able notify the kernel that the underlying store has changed.

Larry

LWN: Comments on "invalidate_page_range() for non-GPL modules"

invalidate_page_range() for non-GPL modules

digging that deeply