Re: [PATCH v2 6/6] RISC-V: Implement sparsemem
From: Logan Gunthorpe
Date: Mon Dec 17 2018 - 11:51:03 EST
On 2018-12-17 7:59 a.m., Nick Kossifidis wrote:
> Having memory blocks of a minimum size of 1GB doesn't make much sense.
> It makes it harder to implement hotplug on top of this since we'll only
> able to add/remove 1GB at a time. ARM used to do the same and they
> switched to 27bits (https://patchwork.kernel.org/patch/9172845/), ARM64
> still uses 1GB, x86 also uses 27bits and most archs also use something
> below 30. I believe we should go for 27bits as well or even better have
> this as a compile time option.
Thanks, that makes sense. I'll make the change for the next time we submit.
> BTW memblocks_present is on master now (got merged 3 days ago).
Great! We'll send an updated patch set after the merge window.