From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@linux.intel.com>,
linux-fsdevel@vger.kernel.org, Jan Kara <jack@suse.cz>,
lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org
Subject: Re: [Lsf-pc] [LSF/MM TOPIC] Support for 1GB THP
Date: Tue, 1 Mar 2016 15:09:19 +0300 [thread overview]
Message-ID: <20160301120919.GA19559@node.shutemov.name> (raw)
In-Reply-To: <20160301115136.GL2747@suse.de>
On Tue, Mar 01, 2016 at 11:51:36AM +0000, Mel Gorman wrote:
> While I know some of these points can be countered and discussed further,
> at the end of the day, the benefits to huge page usage are reduced memory
> usage on page tables, a reduction of TLB pressure and reduced TLB fill
> costs. Until such time as it's known that there are realistic workloads
> that cannot fit in memory due to the page table usage and workloads that
> are limited by TLB pressure, the complexity of huge pages is unjustified
> and the focus should be on the basic features working correctly.
Size of page table can be limiting factor now for workloads that tries to
migrate from 2M hugetlb with shared page tables to DAX. 1G pages is a way
to lower the overhead.
Note, that reduced memory usage on page tables is not there for anon THP,
as we have to deposit these page table to be able split huge pmd (or pud)
at any point.
--
Kirill A. Shutemov
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next prev parent reply other threads:[~2016-03-01 12:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-01 7:09 [LSF/MM TOPIC] Support for 1GB THP Matthew Wilcox
2016-03-01 10:25 ` [Lsf-pc] " Jan Kara
2016-03-01 11:00 ` Mel Gorman
2016-03-01 11:51 ` Mel Gorman
2016-03-01 12:09 ` Kirill A. Shutemov [this message]
2016-03-01 12:52 ` Mel Gorman
2016-03-01 21:44 ` Matthew Wilcox
2016-03-01 22:15 ` Mike Kravetz
2016-03-01 22:33 ` Rik van Riel
2016-03-01 22:36 ` James Bottomley
2016-03-02 14:14 ` Matthew Wilcox
2016-03-01 12:20 ` Kirill A. Shutemov
2016-03-01 16:32 ` Christoph Lameter
2016-03-01 21:47 ` Matthew Wilcox
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