Re: [PATCH v9] mm: support madvise(MADV_FREE)

["Kirill A. Shutemov" <kirill@shutemov.name>]

On Tue, Jul 01, 2014 at 09:36:15AM +0900, Minchan Kim wrote:
> +	do {
> +		/*
> +		 * XXX: We can optimize with supporting Hugepage free
> +		 * if the range covers.
> +		 */
> +		next = pmd_addr_end(addr, end);
> +		if (pmd_trans_huge(*pmd))
> +			split_huge_page_pmd(vma, addr, pmd);

Could you implement proper THP support before upstreaming the feature?
It shouldn't be a big deal.

> +		/*
> +		 * Here there can be other concurrent MADV_DONTNEED or
> +		 * trans huge page faults running, and if the pmd is
> +		 * none or trans huge it can change under us. This is
> +		 * because MADV_LAZYFREE holds the mmap_sem in read
> +		 * mode.
> +		 */
> +		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
> +			goto next;
> +		next = madvise_free_pte_range(tlb, vma, pmd, addr, next);
> +next:
> +		cond_resched();
> +	} while (pmd++, addr = next, addr != end);

-- 
 Kirill A. Shutemov

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