[PATCH -v2 0/9] PI and assorted failings

[Peter Zijlstra]

OK, long time since I posted, but I finally found these patches again.
Hopefully I addressed all feedback from last time (sorry if I missed anything).

Aside from the stuff I posted during review last time, I restructured the first
two patches to get rid of that unparsable changelog.

I folded part of the second patch into the first patch and rewrote the
Changelog for the first patch.

Now the first patch fully restructures the unlock+deboost path and the second
patch only adds the pi_top_task pointer cache. Where previously the first patch
did half the unlock+deboost restructure and the second patch did the rest and
added that cache.

If there are no objections, I'll queue the stuff to finally get rid of these
patches (and not 'loose' them again).