Messages in this thread | | | Date | Fri, 7 Feb 2020 12:11:34 +0800 | From | Baoquan He <> | Subject | Re: [PATCH 2/3] mm/sparsemem: get physical address to page struct instead of virtual address to pfn |
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On 02/07/20 at 07:16am, Wei Yang wrote: > memmap should be the physical address to page struct instead of virtual > address to pfn.
Maybe not, memmap stores a virtual address.
> > Since we call this only for SPARSEMEM_VMEMMAP, pfn_to_page() is valid at > this point. > > Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") > Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> > CC: Dan Williams <dan.j.williams@intel.com> > --- > mm/sparse.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/sparse.c b/mm/sparse.c > index b5da121bdd6e..56816f653588 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -888,7 +888,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, > /* Align memmap to section boundary in the subsection case */ > if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) && > section_nr_to_pfn(section_nr) != start_pfn) > - memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); > + memmap = pfn_to_page(section_nr_to_pfn(section_nr));
With Dan's confirmation, sub-section is only valid in vmemmap case. I think the old if (section_nr_to_pfn(section_nr) != start_pfn) is enough to filter out non vmemmap case. So only below code is good:
+ memmap = pfn_to_page(section_nr_to_pfn(section_nr));
> sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); > > return 0; > -- > 2.17.1 >
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