linux-kernel - Re: [PATCH] mm, hugetlb: don't require CMA for runtime gigantic 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: <56B31A31.3070406@suse.cz>
Date:	Thu, 4 Feb 2016 10:30:25 +0100
From:	Vlastimil Babka <vbabka@...e.cz>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Luiz Capitulino <lcapitulino@...hat.com>,
	"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
	Zhang Yanfei <zhangyanfei@...fujitsu.com>,
	Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	Mel Gorman <mgorman@...hsingularity.net>,
	Davidlohr Bueso <dave@...olabs.net>,
	Hillf Danton <hillf.zj@...baba-inc.com>,
	Mike Kravetz <mike.kravetz@...cle.com>
Subject: Re: [PATCH] mm, hugetlb: don't require CMA for runtime gigantic pages

On 02/04/2016 07:02 AM, Joonsoo Kim wrote:
> On Wed, Feb 03, 2016 at 06:50:11PM +0100, Vlastimil Babka wrote:
>> Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at
>> runtime") has added the runtime gigantic page allocation via
>> alloc_contig_range(), making this support available only when CONFIG_CMA is
>> enabled. Because it doesn't depend on MIGRATE_CMA pageblocks and the
>> associated infrastructure, it is possible with few simple adjustments to
>> require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA.
>>
>> After this patch, alloc_contig_range() and related functions are available
>> and used for gigantic pages with just CONFIG_MEMORY_ISOLATION enabled. Note
>> CONFIG_CMA selects CONFIG_MEMORY_ISOLATION. This allows supporting runtime
>> gigantic pages without the CMA-specific checks in page allocator fastpaths.
>
> You need to set CONFIG_COMPACTION or CONFIG_CMA to use
> isolate_migratepages_range() and others in alloc_contig_range().

Hm, right, thanks for catching this. I admit I didn't try disabling 
compaction during the tests.

> Thanks.
>