Re: [RFC v2 0/2] Do not touch pages in remove_memory path

[Jerome Glisse]

On Tue, Aug 28, 2018 at 01:47:09PM +0200, Oscar Salvador wrote:
> On Fri, Aug 17, 2018 at 05:41:25PM +0200, Oscar Salvador wrote:
> > From: Oscar Salvador <osalvador@xxxxxxx>
> [...]
> > 
> > The main difficulty I faced here was in regard of HMM/devm, as it really handles
> > the hot-add/remove memory particulary, and what is more important,
> > also the resources.
> > 
> > I really scratched my head for ideas about how to handle this case, and
> > after some fails I came up with the idea that we could check for the
> > res->flags.
> > 
> > Memory resources that goes through the "official" memory-hotplug channels
> > have the IORESOURCE_SYSTEM_RAM flag.
> > This flag is made of (IORESOURCE_MEM|IORESOURCE_SYSRAM).
> > 
> > HMM/devm, on the other hand, request and release the resources
> > through devm_request_mem_region/devm_release_mem_region, and 
> > these resources do not contain the IORESOURCE_SYSRAM flag.
> > 
> > So what I ended up doing is to check for IORESOURCE_SYSRAM
> > in release_mem_region_adjustable.
> > If we see that a resource does not have such a flag, we know that
> > we are dealing with a resource coming from HMM/devm, and so,
> > we do not need to do anything as HMM/dev will take care of that part.
> > 
> 
> Jerome/Dan, now that the merge window is closed, and before sending the RFCv3, could you please check
> this and see if you see something that is flagrant wrong? (about devm/HMM)
> 
> If you prefer I can send v3 spliting up even more.
> Maybe this will ease the review.
> 

This looks good to me you can add Reviewed-by: Jérôme Glisse <jglisse@xxxxxxxxxx>