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From: Dan Williams <dan.j.williams@intel.com>
To: Joao Martins <joao.m.martins@oracle.com>
Cc: Linux MM <linux-mm@kvack.org>,
	Vishal Verma <vishal.l.verma@intel.com>,
	 Dave Jiang <dave.jiang@intel.com>,
	Naoya Horiguchi <naoya.horiguchi@nec.com>,
	 Matthew Wilcox <willy@infradead.org>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	John Hubbard <jhubbard@nvidia.com>,
	 Jane Chu <jane.chu@oracle.com>,
	Muchun Song <songmuchun@bytedance.com>,
	 Mike Kravetz <mike.kravetz@oracle.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	 Jonathan Corbet <corbet@lwn.net>,
	Linux NVDIMM <nvdimm@lists.linux.dev>,
	 Linux Doc Mailing List <linux-doc@vger.kernel.org>
Subject: Re: [PATCH v3 07/14] mm/hugetlb_vmemmap: move comment block to Documentation/vm
Date: Tue, 27 Jul 2021 23:09:09 -0700	[thread overview]
Message-ID: <CAPcyv4hMUY+wtB1P4SbzesOB45fo7bZzg14kdX86Hrnd4A-RBQ@mail.gmail.com> (raw)
In-Reply-To: <20210714193542.21857-8-joao.m.martins@oracle.com>

On Wed, Jul 14, 2021 at 12:36 PM Joao Martins <joao.m.martins@oracle.com> wrote:
>
> In preparation for device-dax for using hugetlbfs compound page tail
> deduplication technique, move the comment block explanation into a
> common place in Documentation/vm.
>
> Cc: Muchun Song <songmuchun@bytedance.com>
> Cc: Mike Kravetz <mike.kravetz@oracle.com>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>

Looks good,

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

> ---
>  Documentation/vm/index.rst         |   1 +
>  Documentation/vm/vmemmap_dedup.rst | 170 +++++++++++++++++++++++++++++
>  mm/hugetlb_vmemmap.c               | 162 +--------------------------
>  3 files changed, 172 insertions(+), 161 deletions(-)
>  create mode 100644 Documentation/vm/vmemmap_dedup.rst
>
> diff --git a/Documentation/vm/index.rst b/Documentation/vm/index.rst
> index eff5fbd492d0..edd690afd890 100644
> --- a/Documentation/vm/index.rst
> +++ b/Documentation/vm/index.rst
> @@ -51,5 +51,6 @@ descriptions of data structures and algorithms.
>     split_page_table_lock
>     transhuge
>     unevictable-lru
> +   vmemmap_dedup
>     z3fold
>     zsmalloc
> diff --git a/Documentation/vm/vmemmap_dedup.rst b/Documentation/vm/vmemmap_dedup.rst
> new file mode 100644
> index 000000000000..215ae2ef3bce
> --- /dev/null
> +++ b/Documentation/vm/vmemmap_dedup.rst
> @@ -0,0 +1,170 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +.. _vmemmap_dedup:
> +
> +==================================
> +Free some vmemmap pages of HugeTLB
> +==================================
> +
> +The struct page structures (page structs) are used to describe a physical
> +page frame. By default, there is a one-to-one mapping from a page frame to
> +it's corresponding page struct.
> +
> +HugeTLB pages consist of multiple base page size pages and is supported by
> +many architectures. See hugetlbpage.rst in the Documentation directory for
> +more details. On the x86-64 architecture, HugeTLB pages of size 2MB and 1GB
> +are currently supported. Since the base page size on x86 is 4KB, a 2MB
> +HugeTLB page consists of 512 base pages and a 1GB HugeTLB page consists of
> +4096 base pages. For each base page, there is a corresponding page struct.
> +
> +Within the HugeTLB subsystem, only the first 4 page structs are used to
> +contain unique information about a HugeTLB page. __NR_USED_SUBPAGE provides
> +this upper limit. The only 'useful' information in the remaining page structs
> +is the compound_head field, and this field is the same for all tail pages.
> +
> +By removing redundant page structs for HugeTLB pages, memory can be returned
> +to the buddy allocator for other uses.
> +
> +Different architectures support different HugeTLB pages. For example, the
> +following table is the HugeTLB page size supported by x86 and arm64
> +architectures. Because arm64 supports 4k, 16k, and 64k base pages and
> +supports contiguous entries, so it supports many kinds of sizes of HugeTLB
> +page.
> +
> ++--------------+-----------+-----------------------------------------------+
> +| Architecture | Page Size |                HugeTLB Page Size              |
> ++--------------+-----------+-----------+-----------+-----------+-----------+
> +|    x86-64    |    4KB    |    2MB    |    1GB    |           |           |
> ++--------------+-----------+-----------+-----------+-----------+-----------+
> +|              |    4KB    |   64KB    |    2MB    |    32MB   |    1GB    |
> +|              +-----------+-----------+-----------+-----------+-----------+
> +|    arm64     |   16KB    |    2MB    |   32MB    |     1GB   |           |
> +|              +-----------+-----------+-----------+-----------+-----------+
> +|              |   64KB    |    2MB    |  512MB    |    16GB   |           |
> ++--------------+-----------+-----------+-----------+-----------+-----------+
> +
> +When the system boot up, every HugeTLB page has more than one struct page
> +structs which size is (unit: pages):
> +
> +   struct_size = HugeTLB_Size / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
> +
> +Where HugeTLB_Size is the size of the HugeTLB page. We know that the size
> +of the HugeTLB page is always n times PAGE_SIZE. So we can get the following
> +relationship.
> +
> +   HugeTLB_Size = n * PAGE_SIZE
> +
> +Then,
> +
> +   struct_size = n * PAGE_SIZE / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
> +               = n * sizeof(struct page) / PAGE_SIZE
> +
> +We can use huge mapping at the pud/pmd level for the HugeTLB page.
> +
> +For the HugeTLB page of the pmd level mapping, then
> +
> +   struct_size = n * sizeof(struct page) / PAGE_SIZE
> +               = PAGE_SIZE / sizeof(pte_t) * sizeof(struct page) / PAGE_SIZE
> +               = sizeof(struct page) / sizeof(pte_t)
> +               = 64 / 8
> +               = 8 (pages)
> +
> +Where n is how many pte entries which one page can contains. So the value of
> +n is (PAGE_SIZE / sizeof(pte_t)).
> +
> +This optimization only supports 64-bit system, so the value of sizeof(pte_t)
> +is 8. And this optimization also applicable only when the size of struct page
> +is a power of two. In most cases, the size of struct page is 64 bytes (e.g.
> +x86-64 and arm64). So if we use pmd level mapping for a HugeTLB page, the
> +size of struct page structs of it is 8 page frames which size depends on the
> +size of the base page.
> +
> +For the HugeTLB page of the pud level mapping, then
> +
> +   struct_size = PAGE_SIZE / sizeof(pmd_t) * struct_size(pmd)
> +               = PAGE_SIZE / 8 * 8 (pages)
> +               = PAGE_SIZE (pages)
> +
> +Where the struct_size(pmd) is the size of the struct page structs of a
> +HugeTLB page of the pmd level mapping.
> +
> +E.g.: A 2MB HugeTLB page on x86_64 consists in 8 page frames while 1GB
> +HugeTLB page consists in 4096.
> +
> +Next, we take the pmd level mapping of the HugeTLB page as an example to
> +show the internal implementation of this optimization. There are 8 pages
> +struct page structs associated with a HugeTLB page which is pmd mapped.
> +
> +Here is how things look before optimization.
> +
> +    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
> + +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
> + |           |                     |     0     | -------------> |     0     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     1     | -------------> |     1     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     2     | -------------> |     2     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     3     | -------------> |     3     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     4     | -------------> |     4     |
> + |    PMD    |                     +-----------+                +-----------+
> + |   level   |                     |     5     | -------------> |     5     |
> + |  mapping  |                     +-----------+                +-----------+
> + |           |                     |     6     | -------------> |     6     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     7     | -------------> |     7     |
> + |           |                     +-----------+                +-----------+
> + |           |
> + |           |
> + |           |
> + +-----------+
> +
> +The value of page->compound_head is the same for all tail pages. The first
> +page of page structs (page 0) associated with the HugeTLB page contains the 4
> +page structs necessary to describe the HugeTLB. The only use of the remaining
> +pages of page structs (page 1 to page 7) is to point to page->compound_head.
> +Therefore, we can remap pages 2 to 7 to page 1. Only 2 pages of page structs
> +will be used for each HugeTLB page. This will allow us to free the remaining
> +6 pages to the buddy allocator.
> +
> +Here is how things look after remapping.
> +
> +    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
> + +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
> + |           |                     |     0     | -------------> |     0     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     1     | -------------> |     1     |
> + |           |                     +-----------+                +-----------+
> + |           |                     |     2     | ----------------^ ^ ^ ^ ^ ^
> + |           |                     +-----------+                   | | | | |
> + |           |                     |     3     | ------------------+ | | | |
> + |           |                     +-----------+                     | | | |
> + |           |                     |     4     | --------------------+ | | |
> + |    PMD    |                     +-----------+                       | | |
> + |   level   |                     |     5     | ----------------------+ | |
> + |  mapping  |                     +-----------+                         | |
> + |           |                     |     6     | ------------------------+ |
> + |           |                     +-----------+                           |
> + |           |                     |     7     | --------------------------+
> + |           |                     +-----------+
> + |           |
> + |           |
> + |           |
> + +-----------+
> +
> +When a HugeTLB is freed to the buddy system, we should allocate 6 pages for
> +vmemmap pages and restore the previous mapping relationship.
> +
> +For the HugeTLB page of the pud level mapping. It is similar to the former.
> +We also can use this approach to free (PAGE_SIZE - 2) vmemmap pages.
> +
> +Apart from the HugeTLB page of the pmd/pud level mapping, some architectures
> +(e.g. aarch64) provides a contiguous bit in the translation table entries
> +that hints to the MMU to indicate that it is one of a contiguous set of
> +entries that can be cached in a single TLB entry.
> +
> +The contiguous bit is used to increase the mapping size at the pmd and pte
> +(last) level. So this type of HugeTLB page can be optimized only when its
> +size of the struct page structs is greater than 2 pages.
> +
> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> index c540c21e26f5..e2994e50ddee 100644
> --- a/mm/hugetlb_vmemmap.c
> +++ b/mm/hugetlb_vmemmap.c
> @@ -6,167 +6,7 @@
>   *
>   *     Author: Muchun Song <songmuchun@bytedance.com>
>   *
> - * The struct page structures (page structs) are used to describe a physical
> - * page frame. By default, there is a one-to-one mapping from a page frame to
> - * it's corresponding page struct.
> - *
> - * HugeTLB pages consist of multiple base page size pages and is supported by
> - * many architectures. See hugetlbpage.rst in the Documentation directory for
> - * more details. On the x86-64 architecture, HugeTLB pages of size 2MB and 1GB
> - * are currently supported. Since the base page size on x86 is 4KB, a 2MB
> - * HugeTLB page consists of 512 base pages and a 1GB HugeTLB page consists of
> - * 4096 base pages. For each base page, there is a corresponding page struct.
> - *
> - * Within the HugeTLB subsystem, only the first 4 page structs are used to
> - * contain unique information about a HugeTLB page. __NR_USED_SUBPAGE provides
> - * this upper limit. The only 'useful' information in the remaining page structs
> - * is the compound_head field, and this field is the same for all tail pages.
> - *
> - * By removing redundant page structs for HugeTLB pages, memory can be returned
> - * to the buddy allocator for other uses.
> - *
> - * Different architectures support different HugeTLB pages. For example, the
> - * following table is the HugeTLB page size supported by x86 and arm64
> - * architectures. Because arm64 supports 4k, 16k, and 64k base pages and
> - * supports contiguous entries, so it supports many kinds of sizes of HugeTLB
> - * page.
> - *
> - * +--------------+-----------+-----------------------------------------------+
> - * | Architecture | Page Size |                HugeTLB Page Size              |
> - * +--------------+-----------+-----------+-----------+-----------+-----------+
> - * |    x86-64    |    4KB    |    2MB    |    1GB    |           |           |
> - * +--------------+-----------+-----------+-----------+-----------+-----------+
> - * |              |    4KB    |   64KB    |    2MB    |    32MB   |    1GB    |
> - * |              +-----------+-----------+-----------+-----------+-----------+
> - * |    arm64     |   16KB    |    2MB    |   32MB    |     1GB   |           |
> - * |              +-----------+-----------+-----------+-----------+-----------+
> - * |              |   64KB    |    2MB    |  512MB    |    16GB   |           |
> - * +--------------+-----------+-----------+-----------+-----------+-----------+
> - *
> - * When the system boot up, every HugeTLB page has more than one struct page
> - * structs which size is (unit: pages):
> - *
> - *    struct_size = HugeTLB_Size / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
> - *
> - * Where HugeTLB_Size is the size of the HugeTLB page. We know that the size
> - * of the HugeTLB page is always n times PAGE_SIZE. So we can get the following
> - * relationship.
> - *
> - *    HugeTLB_Size = n * PAGE_SIZE
> - *
> - * Then,
> - *
> - *    struct_size = n * PAGE_SIZE / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
> - *                = n * sizeof(struct page) / PAGE_SIZE
> - *
> - * We can use huge mapping at the pud/pmd level for the HugeTLB page.
> - *
> - * For the HugeTLB page of the pmd level mapping, then
> - *
> - *    struct_size = n * sizeof(struct page) / PAGE_SIZE
> - *                = PAGE_SIZE / sizeof(pte_t) * sizeof(struct page) / PAGE_SIZE
> - *                = sizeof(struct page) / sizeof(pte_t)
> - *                = 64 / 8
> - *                = 8 (pages)
> - *
> - * Where n is how many pte entries which one page can contains. So the value of
> - * n is (PAGE_SIZE / sizeof(pte_t)).
> - *
> - * This optimization only supports 64-bit system, so the value of sizeof(pte_t)
> - * is 8. And this optimization also applicable only when the size of struct page
> - * is a power of two. In most cases, the size of struct page is 64 bytes (e.g.
> - * x86-64 and arm64). So if we use pmd level mapping for a HugeTLB page, the
> - * size of struct page structs of it is 8 page frames which size depends on the
> - * size of the base page.
> - *
> - * For the HugeTLB page of the pud level mapping, then
> - *
> - *    struct_size = PAGE_SIZE / sizeof(pmd_t) * struct_size(pmd)
> - *                = PAGE_SIZE / 8 * 8 (pages)
> - *                = PAGE_SIZE (pages)
> - *
> - * Where the struct_size(pmd) is the size of the struct page structs of a
> - * HugeTLB page of the pmd level mapping.
> - *
> - * E.g.: A 2MB HugeTLB page on x86_64 consists in 8 page frames while 1GB
> - * HugeTLB page consists in 4096.
> - *
> - * Next, we take the pmd level mapping of the HugeTLB page as an example to
> - * show the internal implementation of this optimization. There are 8 pages
> - * struct page structs associated with a HugeTLB page which is pmd mapped.
> - *
> - * Here is how things look before optimization.
> - *
> - *    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
> - * +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
> - * |           |                     |     0     | -------------> |     0     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     1     | -------------> |     1     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     2     | -------------> |     2     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     3     | -------------> |     3     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     4     | -------------> |     4     |
> - * |    PMD    |                     +-----------+                +-----------+
> - * |   level   |                     |     5     | -------------> |     5     |
> - * |  mapping  |                     +-----------+                +-----------+
> - * |           |                     |     6     | -------------> |     6     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     7     | -------------> |     7     |
> - * |           |                     +-----------+                +-----------+
> - * |           |
> - * |           |
> - * |           |
> - * +-----------+
> - *
> - * The value of page->compound_head is the same for all tail pages. The first
> - * page of page structs (page 0) associated with the HugeTLB page contains the 4
> - * page structs necessary to describe the HugeTLB. The only use of the remaining
> - * pages of page structs (page 1 to page 7) is to point to page->compound_head.
> - * Therefore, we can remap pages 2 to 7 to page 1. Only 2 pages of page structs
> - * will be used for each HugeTLB page. This will allow us to free the remaining
> - * 6 pages to the buddy allocator.
> - *
> - * Here is how things look after remapping.
> - *
> - *    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
> - * +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
> - * |           |                     |     0     | -------------> |     0     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     1     | -------------> |     1     |
> - * |           |                     +-----------+                +-----------+
> - * |           |                     |     2     | ----------------^ ^ ^ ^ ^ ^
> - * |           |                     +-----------+                   | | | | |
> - * |           |                     |     3     | ------------------+ | | | |
> - * |           |                     +-----------+                     | | | |
> - * |           |                     |     4     | --------------------+ | | |
> - * |    PMD    |                     +-----------+                       | | |
> - * |   level   |                     |     5     | ----------------------+ | |
> - * |  mapping  |                     +-----------+                         | |
> - * |           |                     |     6     | ------------------------+ |
> - * |           |                     +-----------+                           |
> - * |           |                     |     7     | --------------------------+
> - * |           |                     +-----------+
> - * |           |
> - * |           |
> - * |           |
> - * +-----------+
> - *
> - * When a HugeTLB is freed to the buddy system, we should allocate 6 pages for
> - * vmemmap pages and restore the previous mapping relationship.
> - *
> - * For the HugeTLB page of the pud level mapping. It is similar to the former.
> - * We also can use this approach to free (PAGE_SIZE - 2) vmemmap pages.
> - *
> - * Apart from the HugeTLB page of the pmd/pud level mapping, some architectures
> - * (e.g. aarch64) provides a contiguous bit in the translation table entries
> - * that hints to the MMU to indicate that it is one of a contiguous set of
> - * entries that can be cached in a single TLB entry.
> - *
> - * The contiguous bit is used to increase the mapping size at the pmd and pte
> - * (last) level. So this type of HugeTLB page can be optimized only when its
> - * size of the struct page structs is greater than 2 pages.
> + * See Documentation/vm/vmemmap_dedup.rst
>   */
>  #define pr_fmt(fmt)    "HugeTLB: " fmt
>
> --
> 2.17.1
>

  parent reply	other threads:[~2021-07-28  6:09 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-14 19:35 [PATCH v3 00/14] mm, sparse-vmemmap: Introduce compound pagemaps Joao Martins
2021-07-14 19:35 ` [PATCH v3 01/14] memory-failure: fetch compound_head after pgmap_pfn_valid() Joao Martins
2021-07-15  0:17   ` Dan Williams
2021-07-15  2:51   ` [External] " Muchun Song
2021-07-15  6:40     ` Christoph Hellwig
2021-07-15  9:19       ` Muchun Song
2021-07-15 13:17     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 02/14] mm/page_alloc: split prep_compound_page into head and tail subparts Joao Martins
2021-07-15  0:19   ` Dan Williams
2021-07-15  2:53   ` [External] " Muchun Song
2021-07-15 13:17     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 03/14] mm/page_alloc: refactor memmap_init_zone_device() page init Joao Martins
2021-07-15  0:20   ` Dan Williams
2021-07-14 19:35 ` [PATCH v3 04/14] mm/memremap: add ZONE_DEVICE support for compound pages Joao Martins
2021-07-15  1:08   ` Dan Williams
2021-07-15 12:52     ` Joao Martins
2021-07-15 13:06       ` Joao Martins
2021-07-15 19:48       ` Dan Williams
2021-07-30 16:13         ` Joao Martins
2021-07-22  0:38       ` Jane Chu
2021-07-22 10:56         ` Joao Martins
2021-07-15 12:59     ` Christoph Hellwig
2021-07-15 13:15       ` Joao Martins
2021-07-15  6:48   ` Christoph Hellwig
2021-07-15 13:15     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 05/14] mm/sparse-vmemmap: add a pgmap argument to section activation Joao Martins
2021-07-28  5:56   ` Dan Williams
2021-07-28  9:43     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 06/14] mm/sparse-vmemmap: refactor core of vmemmap_populate_basepages() to helper Joao Martins
2021-07-28  6:04   ` Dan Williams
2021-07-28 10:48     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 07/14] mm/hugetlb_vmemmap: move comment block to Documentation/vm Joao Martins
2021-07-15  2:47   ` [External] " Muchun Song
2021-07-15 13:16     ` Joao Martins
2021-07-28  6:09   ` Dan Williams [this message]
2021-07-14 19:35 ` [PATCH v3 08/14] mm/sparse-vmemmap: populate compound pagemaps Joao Martins
2021-07-28  6:55   ` Dan Williams
2021-07-28 15:35     ` Joao Martins
2021-07-28 18:03       ` Dan Williams
2021-07-28 18:54         ` Joao Martins
2021-07-28 20:04           ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 09/14] mm/page_alloc: reuse tail struct pages for " Joao Martins
2021-07-28  7:28   ` Dan Williams
2021-07-28 15:56     ` Joao Martins
2021-07-28 16:08       ` Dan Williams
2021-07-28 16:12         ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 10/14] device-dax: use ALIGN() for determining pgoff Joao Martins
2021-07-28  7:29   ` Dan Williams
2021-07-28 15:56     ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 11/14] device-dax: ensure dev_dax->pgmap is valid for dynamic devices Joao Martins
2021-07-28  7:30   ` Dan Williams
2021-07-28 15:56     ` Joao Martins
2021-08-06 12:28       ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 12/14] device-dax: compound pagemap support Joao Martins
2021-07-14 23:36   ` Dan Williams
2021-07-15 12:00     ` Joao Martins
2021-07-27 23:51       ` Dan Williams
2021-07-28  9:36         ` Joao Martins
2021-07-28 18:51           ` Dan Williams
2021-07-28 18:59             ` Joao Martins
2021-07-28 19:03               ` Dan Williams
2021-07-14 19:35 ` [PATCH v3 13/14] mm/gup: grab head page refcount once for group of subpages Joao Martins
2021-07-28 19:55   ` Dan Williams
2021-07-28 20:07     ` Joao Martins
2021-07-28 20:23       ` Dan Williams
2021-08-25 19:10         ` Joao Martins
2021-08-25 19:15           ` Matthew Wilcox
2021-08-25 19:26             ` Joao Martins
2021-07-14 19:35 ` [PATCH v3 14/14] mm/sparse-vmemmap: improve memory savings for compound pud geometry Joao Martins
2021-07-28 20:03   ` Dan Williams
2021-07-28 20:08     ` Joao Martins
2021-07-14 21:48 ` [PATCH v3 00/14] mm, sparse-vmemmap: Introduce compound pagemaps Andrew Morton
2021-07-14 23:47   ` Dan Williams
2021-07-22  2:24   ` Matthew Wilcox
2021-07-22 10:53     ` Joao Martins
2021-07-27 23:23       ` Dan Williams
2021-08-02 10:40         ` Joao Martins
2021-08-02 14:06           ` Dan Williams

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