Re: [PATCH 25 of 28] transparent hugepage core

[Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>]

Hi.

> +static int __do_huge_anonymous_page(struct mm_struct *mm,
> +				    struct vm_area_struct *vma,
> +				    unsigned long address, pmd_t *pmd,
> +				    struct page *page,
> +				    unsigned long haddr)
> +{
> +	int ret = 0;
> +	pgtable_t pgtable;
> +
> +	VM_BUG_ON(!PageCompound(page));
> +	pgtable = pte_alloc_one(mm, address);
> +	if (unlikely(!pgtable)) {
> +		put_page(page);
> +		return VM_FAULT_OOM;
> +	}
> +
> +	clear_huge_page(page, haddr, HPAGE_NR);
> +
> +	__SetPageUptodate(page);
> +	smp_wmb();
> +
> +	spin_lock(&mm->page_table_lock);
> +	if (unlikely(!pmd_none(*pmd))) {
> +		put_page(page);
> +		pte_free(mm, pgtable);
> +	} else {
> +		pmd_t entry;
> +		entry = mk_pmd(page, vma->vm_page_prot);
> +		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
> +		entry = pmd_mkhuge(entry);
> +		page_add_new_anon_rmap(page, vma, haddr);
> +		set_pmd_at(mm, haddr, pmd, entry);
> +		prepare_pmd_huge_pte(pgtable, mm);
> +	}
> +	spin_unlock(&mm->page_table_lock);
> +	
> +	return ret;
> +}
> +
IIUC, page_add_new_anon_rmap()(and add_page_to_lru_list(), which will be called
by the call path) will update zone state of NR_ANON_PAGES and NR_ACTIVE_ANON.
Shouldn't we also modify zone state codes to support transparent hugepage support ?


Thanks,
Daisuke Nishimura.

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