Re: [PATCH BUGFIX V3] block, bfq: add requeue-request hook

[Mike Galbraith <efault@gmx.de>]

On Mon, 2018-02-12 at 13:48 +0100, Oleksandr Natalenko wrote:
> Hi.
> 
> 12.02.2018 12:22, Mike Galbraith wrote:
> > How does that work without someone actually submitting patches? ï¿œCC
> > stable and pass along a conveniently sorted cherry-pick list?
> 
>  From my experience, Greg is fine with the list of hashes, but he needs 
> an approval from the relevant subtree maintainer (Jens in this case).

Oh dear. ï¿œI'm a bit reluctant to even mention this, buuut, when
creating that hash list, I extracted/applied them to 4.15.3 via quilt
to make sure that they really do slip right in.. and later, while
building two fat enterprise config kernels concurrently, trees living
in separate spinning rust buckets, box IO stalled on me. ï¿œNot good.
ï¿œHard reboot, clean up and try it again, it reproduced. ï¿œSwitch to
master, that reproduced. ï¿œExtra not good.

I found that rather odd, because I had earlier done this to 4.15..

patches/block-bfq:-fix-occurrences-of-request-finish-method-s-old-name.patch
patches/block-bfq:-add-requeue-request-hook.patch

..ie take only the rename, wedge the fix in on top of it, beat on box,
it worked fine. ï¿œThis morning, I go back to only those two, and box is
again (at least pretending to be) perfectly happy to build the same
trees it hung on twice in a row yesterday, it _seems_ to be completely
uninterested in stalling no matter what I do.

So, something not so funny is still going on, here at least. ï¿œTest
results imply that something in that hash list _may_ not be all that
desirable a thing to send to stable, but who knows, some playful
gremlin may well be pulling my chain, will let box stall on me again a
few seconds after I write that, and poke send :)

Ok IO gremlin, go for it...

	-Mike