From: David Hildenbrand <david@redhat.com>
To: Zi Yan <ziy@nvidia.com>,
linux-mm@kvack.org,
"Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>,
Hugh Dickins <hughd@google.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Yang Shi <yang@os.amperecomputing.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Yu Zhao <yuzhao@google.com>, John Hubbard <jhubbard@nvidia.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 0/1] Buddy allocator like folio split
Date: Fri, 18 Oct 2024 20:42:22 +0200 [thread overview]
Message-ID: <7ec81ff8-5645-42a1-a048-c8700aff07fa@redhat.com> (raw)
In-Reply-To: <20241008223748.555845-1-ziy@nvidia.com>
On 09.10.24 00:37, Zi Yan wrote:
> Hi all,
Hi!
>
> Matthew and I have discussed about a different way of splitting large
> folios. Instead of split one folio uniformly into the same order smaller
> ones, doing buddy allocator like split can reduce the total number of
> resulting folios, the amount of memory needed for multi-index xarray
> split, and keep more large folios after a split. In addition, both
> Hugh[1] and Ryan[2] had similar suggestions before.
>
> The patch is an initial implementation. It passes simple order-9 to
> lower order split tests for anonymous folios and pagecache folios.
> There are still a lot of TODOs to make it upstream. But I would like to gather
> feedbacks before that.
Interesting, but I don't see any actual users besides the debug/test
interface wired up.
I assume ftruncate() / fallocate(PUNCH_HOLE) might be good use cases?
For example, when punching 1M of a 2M folio, we can just leave a 1M
folio in the pagecache.
Any other obvious users you have in mind?
--
Cheers,
David / dhildenb
next prev parent reply other threads:[~2024-10-18 18:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-08 22:37 Zi Yan
2024-10-08 22:37 ` [RFC PATCH 1/1] mm/huge_memory: buddy allocator like folio_split() Zi Yan
2024-10-09 9:54 ` [RFC PATCH 0/1] Buddy allocator like folio split Kirill A. Shutemov
2024-10-09 14:21 ` Zi Yan
2024-10-18 18:42 ` David Hildenbrand [this message]
2024-10-18 19:10 ` Zi Yan
2024-10-18 19:44 ` Yang Shi
2024-10-18 19:59 ` David Hildenbrand
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