From: Matthew Wilcox <willy@infradead.org>
To: David Hildenbrand <david@redhat.com>
Cc: "Wei Yang" <richard.weiyang@gmail.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
"Andrew Morton" <akpm@linux-foundation.org>,
"Tejun Heo" <tj@kernel.org>, "Zefan Li" <lizefan.x@bytedance.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Michal Koutný" <mkoutny@suse.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Muchun Song" <muchun.song@linux.dev>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
"Lorenzo Stoakes" <lorenzo.stoakes@oracle.com>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Jann Horn" <jannh@google.com>
Subject: Re: [PATCH v3 20/20] mm: stop maintaining the per-page mapcount of large folios (CONFIG_NO_PAGE_MAPCOUNT)
Date: Tue, 14 Oct 2025 15:32:41 +0100 [thread overview]
Message-ID: <aO5fCT62gZZw9-wQ@casper.infradead.org> (raw)
In-Reply-To: <71380b43-c23c-42b5-8aab-f158bb37bc75@redhat.com>
On Tue, Oct 14, 2025 at 02:59:30PM +0200, David Hildenbrand wrote:
> > As commit 349994cf61e6 mentioned, we don't support partially mapped PUD-sized
> > folio yet.
>
> We do support partially mapped PUD-sized folios I think, but not anonymous
> PUD-sized folios.
I don't think so? The only mechanism I know of to allocate PUD-sized
chunks of memory is hugetlb, and that doesn't permit partial mappings.
next prev parent reply other threads:[~2025-10-14 14:32 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-03 16:29 [PATCH v3 00/20] mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 01/20] mm: factor out large folio handling from folio_order() into folio_large_order() David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 02/20] mm: factor out large folio handling from folio_nr_pages() into folio_large_nr_pages() David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 03/20] mm: let _folio_nr_pages overlay memcg_data in first tail page David Hildenbrand
2025-03-05 10:29 ` David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 04/20] mm: move hugetlb specific things in folio to page[3] David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 05/20] mm: move _pincount in folio to page[2] on 32bit David Hildenbrand
2025-03-03 16:29 ` [PATCH v3 06/20] mm: move _entire_mapcount " David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 07/20] mm/rmap: pass dst_vma to folio_dup_file_rmap_pte() and friends David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 08/20] mm/rmap: pass vma to __folio_add_rmap() David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 09/20] mm/rmap: abstract large mapcount operations for large folios (!hugetlb) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 10/20] bit_spinlock: __always_inline (un)lock functions David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 11/20] mm/rmap: use folio_large_nr_pages() in add/remove functions David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 12/20] mm/rmap: basic MM owner tracking for large folios (!hugetlb) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 13/20] mm: Copy-on-Write (COW) reuse support for PTE-mapped THP David Hildenbrand
2025-04-19 16:02 ` Kairui Song
2025-04-19 16:25 ` David Hildenbrand
2025-04-19 16:32 ` David Hildenbrand
2025-04-19 16:35 ` Kairui Song
2025-04-22 2:52 ` Kairui Song
2025-04-22 7:05 ` David Hildenbrand
2025-04-19 16:33 ` Kairui Song
2025-03-03 16:30 ` [PATCH v3 14/20] mm: convert folio_likely_mapped_shared() to folio_maybe_mapped_shared() David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 15/20] mm: CONFIG_NO_PAGE_MAPCOUNT to prepare for not maintain per-page mapcounts in large folios David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 16/20] fs/proc/page: remove per-page mapcount dependency for /proc/kpagecount (CONFIG_NO_PAGE_MAPCOUNT) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 17/20] fs/proc/task_mmu: remove per-page mapcount dependency for PM_MMAP_EXCLUSIVE (CONFIG_NO_PAGE_MAPCOUNT) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 18/20] fs/proc/task_mmu: remove per-page mapcount dependency for "mapmax" (CONFIG_NO_PAGE_MAPCOUNT) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 19/20] fs/proc/task_mmu: remove per-page mapcount dependency for smaps/smaps_rollup (CONFIG_NO_PAGE_MAPCOUNT) David Hildenbrand
2025-03-03 16:30 ` [PATCH v3 20/20] mm: stop maintaining the per-page mapcount of large folios (CONFIG_NO_PAGE_MAPCOUNT) David Hildenbrand
2025-10-14 12:23 ` Wei Yang
2025-10-14 12:59 ` David Hildenbrand
2025-10-14 13:31 ` Wei Yang
2025-10-14 14:32 ` Matthew Wilcox [this message]
2025-10-14 14:38 ` David Hildenbrand
2025-10-15 0:45 ` Wei Yang
2025-10-20 13:53 ` David Hildenbrand
2025-03-03 22:43 ` [PATCH v3 00/20] mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT Andrew Morton
2025-03-04 10:21 ` David Hildenbrand
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