Messages in this thread | | | Date | Fri, 07 Dec 2012 14:43:46 +0800 | From | Tang Chen <> | Subject | Re: [Patch v4 09/12] memory-hotplug: remove page table of x86_64 architecture |
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On 11/27/2012 06:00 PM, Wen Congyang wrote: > For hot removing memory, we sholud remove page table about the memory. > So the patch searches a page table about the removed memory, and clear > page table.
(snip)
> +void __meminit > +kernel_physical_mapping_remove(unsigned long start, unsigned long end) > +{ > + unsigned long next; > + bool pgd_changed = false; > + > + start = (unsigned long)__va(start); > + end = (unsigned long)__va(end);
Hi Wu,
Here, you expect start and end are physical addresses. But in phys_xxx_remove() function, I think using virtual addresses is just fine. Functions like pmd_addr_end() and pud_index() only calculate an offset.
So, would you please tell me if we have to use physical addresses here ?
Thanks. :)
> + > + for (; start< end; start = next) { > + pgd_t *pgd = pgd_offset_k(start); > + pud_t *pud; > + > + next = pgd_addr_end(start, end); > + > + if (!pgd_present(*pgd)) > + continue; > + > + pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); > + phys_pud_remove(pud, __pa(start), __pa(next)); > + if (free_pud_table(pud, pgd)) > + pgd_changed = true; > + unmap_low_page(pud); > + } > + > + if (pgd_changed) > + sync_global_pgds(start, end - 1); > + > + flush_tlb_all(); > +} > + > #ifdef CONFIG_MEMORY_HOTREMOVE > int __ref arch_remove_memory(u64 start, u64 size) > { > @@ -692,6 +921,8 @@ int __ref arch_remove_memory(u64 start, u64 size) > ret = __remove_pages(zone, start_pfn, nr_pages); > WARN_ON_ONCE(ret); > > + kernel_physical_mapping_remove(start, start + size); > + > return ret; > } > #endif
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