From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/7] mm: Store compound_nr as well as compound_order
Date: Mon, 6 Jul 2020 13:29:25 +0300 [thread overview]
Message-ID: <20200706102925.ot3vgdg5mnr5d4gh@box> (raw)
In-Reply-To: <20200629151959.15779-2-willy@infradead.org>
On Mon, Jun 29, 2020 at 04:19:53PM +0100, Matthew Wilcox (Oracle) wrote:
> This removes a few instructions from functions which need to know how many
> pages are in a compound page. The storage used is either page->mapping
> on 64-bit or page->index on 32-bit. Both of these are fine to overlay
> on tail pages.
I'm not a fan of redundant data in struct page, even if it's less busy
tail page. We tend to find more use of the space over time.
Any numbers on what it gives for typical kernel? Does it really worth it?
--
Kirill A. Shutemov
next prev parent reply other threads:[~2020-07-06 10:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-29 15:19 [PATCH 0/7] THP prep patches Matthew Wilcox (Oracle)
2020-06-29 15:19 ` [PATCH 1/7] mm: Store compound_nr as well as compound_order Matthew Wilcox (Oracle)
2020-06-29 16:22 ` Ira Weiny
2020-06-29 16:24 ` Matthew Wilcox
2020-07-06 10:29 ` Kirill A. Shutemov [this message]
2020-08-11 22:53 ` Matthew Wilcox
2020-06-29 15:19 ` [PATCH 2/7] mm: Move page-flags include to top of file Matthew Wilcox (Oracle)
2020-06-29 15:19 ` [PATCH 3/7] mm: Add thp_order Matthew Wilcox (Oracle)
2020-06-29 15:19 ` [PATCH 4/7] mm: Add thp_size Matthew Wilcox (Oracle)
2020-06-29 15:19 ` [PATCH 5/7] mm: Replace hpage_nr_pages with thp_nr_pages Matthew Wilcox (Oracle)
2020-06-29 17:40 ` Mike Kravetz
2020-06-29 18:14 ` Matthew Wilcox
2020-06-29 18:32 ` Matthew Wilcox
2020-07-01 1:33 ` Andrew Morton
2020-06-29 15:19 ` [PATCH 6/7] mm: Add thp_head Matthew Wilcox (Oracle)
2020-06-29 15:19 ` [PATCH 7/7] mm: Introduce offset_in_thp Matthew Wilcox (Oracle)
2020-06-29 17:11 ` [PATCH 0/7] THP prep patches William Kucharski
2020-06-29 18:13 ` Zi Yan
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