Re: revamp vmem_altmap / dev_pagemap handling V3

On Mon 08-01-18 13:27:13, Dan Williams wrote:

On Mon, Jan 8, 2018 at 12:25 PM, Michal Hocko [off-list ref] wrote:

quoted

On Mon 08-01-18 11:44:02, Dan Williams wrote:

quoted

On Mon, Jan 8, 2018 at 3:26 AM, Christoph Hellwig [off-list ref] wrote:

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Any chance to get this fully reviewed and picked up before the
end of the merge window?

I'm fine carrying these through the nvdimm tree, but I'd need an ack
from the mm folks for all the code touches related to arch_add_memory.

I am sorry to be slow here but I am out of time right now - yeah having
a lot of fun kaiser time. I didn't get to look at these patches at all
yet but the changelog suggests that you want to remove vmem_altmap.
I've had plans to (ab)use this for self hosted struct pages for memory
hotplug http://lkml.kernel.org/r/20170801124111.28881-1-mhocko@kernel.org
That work is stalled though because it is buggy and I was too busy to
finish that work. Anyway, if you believe that removing vmem_altmap is a
good step in general I will find another way. I wasn't really happy how
the whole thing is grafted to the memory hotplug and (ab)used it only
because it was handy and ready for reuse.

You misread, these are keeping vmem_altmap and cleaning up the usage
to pass the vmem_altmap pointer through all paths rather than the
tricky radix lookup we were doing previously.

Good to hear. I really didn't get further than reading through email
subjects and for some reason I misread those.

quoted

Anyway if you need a review of mm parts from me, you will have to wait
some more. If this requires some priority then go ahead and merge
it. Times are just too crazy right now.

Since you were planning on reusing vmem_altmap I think these patches
make your job easier. I don't see the risk in merging these, we've
squeezed out a few bugs and all the nvdimm unit tests are passing.

Good, then really do not wait for me if this aims to get merged soon.

quoted

Sorry about that.

No worries, quite a few of us are in that same boat.

Yeah the boat is quite large I suspect...

-- 
Michal Hocko
SUSE Labs