linux-kernel - Re: [PATCHv3, RESEND 6/8] khugepaged: Allow to collapse PTE-mapped compound pages

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: <20200415144426.a146ef173140f5bc396a6dcd@linux-foundation.org>
Date:   Wed, 15 Apr 2020 14:44:26 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Cc:     Andrea Arcangeli <aarcange@...hat.com>, Zi Yan <ziy@...dia.com>,
        Yang Shi <yang.shi@...ux.alibaba.com>,
        Ralph Campbell <rcampbell@...dia.com>,
        John Hubbard <jhubbard@...dia.com>,
        William Kucharski <william.kucharski@...cle.com>,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCHv3, RESEND 6/8] khugepaged: Allow to collapse PTE-mapped
 compound pages

On Mon, 13 Apr 2020 15:52:18 +0300 "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com> wrote:

> We can collapse PTE-mapped compound pages. We only need to avoid
> handling them more than once: lock/unlock page only once if it's present
> in the PMD range multiple times as it handled on compound level. The
> same goes for LRU isolation and putback.
> 
> ...
>
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -515,17 +515,30 @@ void __khugepaged_exit(struct mm_struct *mm)
>  
>  static void release_pte_page(struct page *page)
>  {
> -	dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page));

I have

	dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page));

here.  Is there some prerequisite which I wasn't able to find?