Messages in this thread Patch in this message | | | Date | Fri, 14 Sep 2012 13:14:28 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH RESEND] memory hotplug: fix a double register section info bug |
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On Fri, 14 Sep 2012 20:00:09 +0900 Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> wrote:
> > @@ -187,9 +184,10 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) > > end_pfn = pfn + pgdat->node_spanned_pages; > > > > /* register_section info */ > > - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) > > - register_page_bootmem_info_section(pfn); > > - > > + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { > > + if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) > > I cannot judge whether your configuration is correct or not. > Thus if it is correct, I want a comment of why the node check is > needed. In usual configuration, a node does not span the other one. > So it is natural that "pfn_to_nid(pfn) is same as "pgdat->node_id". > Thus we may remove the node check in the future.
yup. How does this look?
--- a/mm/memory_hotplug.c~memory-hotplug-fix-a-double-register-section-info-bug-fix +++ a/mm/memory_hotplug.c @@ -185,6 +185,12 @@ void register_page_bootmem_info_node(str /* register_section info */ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + /* + * Some platforms can assign the same pfn to multiple nodes - on + * node0 as well as nodeN. To avoid registering a pfn against + * multiple nodes we check that this pfn does not already + * reside in some other node. + */ if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) register_page_bootmem_info_section(pfn); } _
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