linux-kernel - Re: [PATCH 1/4] mm/hugetlb: Enable PUD level huge page migration

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: <835085a2-79c2-4eb5-2c10-13bb2893f611@arm.com>
Date:   Tue, 2 Oct 2018 13:38:01 +0100
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     Anshuman Khandual <anshuman.khandual@....com>, linux-mm@...ck.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:     punit.agrawal@....com, will.deacon@....com, Steven.Price@....com,
        catalin.marinas@....com, mhocko@...nel.org,
        mike.kravetz@...cle.com, n-horiguchi@...jp.nec.com
Subject: Re: [PATCH 1/4] mm/hugetlb: Enable PUD level huge page migration

Hi Anshuman

On 02/10/18 13:15, Anshuman Khandual wrote:
> Architectures like arm64 have PUD level HugeTLB pages for certain configs
> (1GB huge page is PUD based on ARM64_4K_PAGES base page size) that can be
> enabled for migration. It can be achieved through checking for PUD_SHIFT
> order based HugeTLB pages during migration.
> 
> Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
> ---
>   include/linux/hugetlb.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 6b68e34..9c1b77f 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -483,7 +483,8 @@ static inline bool hugepage_migration_supported(struct hstate *h)
>   {
>   #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
>   	if ((huge_page_shift(h) == PMD_SHIFT) ||
> -		(huge_page_shift(h) == PGDIR_SHIFT))
> +		(huge_page_shift(h) == PUD_SHIFT) ||


> +			(huge_page_shift(h) == PGDIR_SHIFT))

nit: Extra Tab ^^.
Also, if only arm64 supports PUD_SHIFT, should this be added only in the 
arm64 specific backend, which we introduce later ?

Suzuki