Re: mm: BUG in do_huge_pmd_wp_page

[Sasha Levin]

It also breaks fairly quickly under testing because:

On 04/07/2014 10:48 AM, Kirill A. Shutemov wrote:
> +	if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) {
> +		spin_lock(ptl);

^ We go into atomic

> +		if (unlikely(!pmd_same(*pmd, orig_pmd)))
> +			goto out_race;
> +	}
> +
>  	if (!page)
>  		clear_huge_page(new_page, haddr, HPAGE_PMD_NR);
>  	else
>  		copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);

copy_user_huge_page() doesn't like running in atomic state,
and asserts might_sleep().


Thanks,
Sasha
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