linux-kernel - Re: [PATCHv5 08/28] khugepaged: ignore pmd tables with THP mapped with ptes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5555EDA1.60202@suse.cz>
Date:	Fri, 15 May 2015 14:59:13 +0200
From:	Vlastimil Babka <vbabka@...e.cz>
To:	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Hugh Dickins <hughd@...gle.com>
CC:	Dave Hansen <dave.hansen@...el.com>, Mel Gorman <mgorman@...e.de>,
	Rik van Riel <riel@...hat.com>,
	Christoph Lameter <cl@...two.org>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	Steve Capper <steve.capper@...aro.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Michal Hocko <mhocko@...e.cz>,
	Jerome Marchand <jmarchan@...hat.com>,
	Sasha Levin <sasha.levin@...cle.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCHv5 08/28] khugepaged: ignore pmd tables with THP mapped
 with ptes

On 04/23/2015 11:03 PM, Kirill A. Shutemov wrote:
> Prepare khugepaged to see compound pages mapped with pte. For now we
> won't collapse the pmd table with such pte.
>
> khugepaged is subject for future rework wrt new refcounting.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
> Tested-by: Sasha Levin <sasha.levin@...cle.com>

Acked-by: Vlastimil Babka <vbabka@...e.cz>

> ---
>   mm/huge_memory.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index fa3d4f78b716..ffc30e4462c1 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2653,6 +2653,11 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
>   		page = vm_normal_page(vma, _address, pteval);
>   		if (unlikely(!page))
>   			goto out_unmap;
> +
> +		/* TODO: teach khugepaged to collapse THP mapped with pte */
> +		if (PageCompound(page))
> +			goto out_unmap;
> +
>   		/*
>   		 * Record which node the original page is from and save this
>   		 * information to khugepaged_node_load[].
> @@ -2663,7 +2668,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
>   		if (khugepaged_scan_abort(node))
>   			goto out_unmap;
>   		khugepaged_node_load[node]++;
> -		VM_BUG_ON_PAGE(PageCompound(page), page);
>   		if (!PageLRU(page) || PageLocked(page) || !PageAnon(page))
>   			goto out_unmap;
>   		/*
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/