Messages in this thread | | | Date | Tue, 28 Aug 2018 13:47:09 +0200 | From | Oscar Salvador <> | Subject | Re: [RFC v2 0/2] Do not touch pages in remove_memory path |
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On Fri, Aug 17, 2018 at 05:41:25PM +0200, Oscar Salvador wrote: > From: Oscar Salvador <osalvador@suse.de> [...] > > 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.
Thanks -- Oscar Salvador SUSE L3
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