linux/mm
Peter Xu 607c63195d mm/gup: drop gup_fast_folio_allowed() in hugepd processing
Hugepd format for GUP is only used in PowerPC with hugetlbfs.  There are
some kernel usage of hugepd (can refer to hugepd_populate_kernel() for
PPC_8XX), however those pages are not candidates for GUP.

Commit a6e79df92e ("mm/gup: disallow FOLL_LONGTERM GUP-fast writing to
file-backed mappings") added a check to fail gup-fast if there's potential
risk of violating GUP over writeback file systems.  That should never
apply to hugepd.  Considering that hugepd is an old format (and even
software-only), there's no plan to extend hugepd into other file typed
memories that is prone to the same issue.

Drop that check, not only because it'll never be true for hugepd per any
known plan, but also it paves way for reusing the function outside
fast-gup.

To make sure we'll still remember this issue just in case hugepd will be
extended to support non-hugetlbfs memories, add a rich comment above
gup_huge_pd(), explaining the issue with proper references.

[akpm@linux-foundation.org: fix comment, per David]
Link: https://lkml.kernel.org/r/20240327152332.950956-7-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:21 -07:00
..
damon mm: madvise: pageout: ignore references rather than clearing young 2024-03-04 17:01:18 -08:00
kasan fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
kfence mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
kmsan mm: kmsan: remove runtime checks from kmsan_unpoison_memory() 2024-02-22 10:24:41 -08:00
backing-dev.c mm: backing-dev: use group allocation/free of per-cpu counters API 2024-04-25 20:56:12 -07:00
balloon_compaction.c
bootmem_info.c bootmem: use kmemleak_free_part_phys in put_page_bootmem 2023-10-25 16:47:13 -07:00
cma_debug.c
cma_sysfs.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma.h mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
compaction.c mm: enable page allocation tagging 2024-04-25 20:55:54 -07:00
debug_page_alloc.c mm: page_alloc: consolidate free page accounting 2024-04-25 20:56:04 -07:00
debug_page_ref.c
debug_vm_pgtable.c fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
debug.c mm: improve dumping of mapcount and page_type 2024-04-25 20:56:00 -07:00
dmapool_test.c
dmapool.c mm/mempool/dmapool: remove CONFIG_DEBUG_SLAB ifdefs 2023-12-05 11:17:58 +01:00
early_ioremap.c
fadvise.c
fail_page_alloc.c
failslab.c
filemap.c mm/filemap: optimize filemap folio adding 2024-04-25 20:56:09 -07:00
folio-compat.c mm: remove page_add_new_anon_rmap and lru_cache_add_inactive_or_unevictable 2023-12-29 11:58:27 -08:00
gup_test.c
gup_test.h
gup.c mm/gup: drop gup_fast_folio_allowed() in hugepd processing 2024-04-25 20:56:21 -07:00
highmem.c x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs 2023-12-29 12:22:28 -08:00
hmm.c mm/treewide: replace pXd_huge() with pXd_leaf() 2024-04-25 20:55:46 -07:00
huge_memory.c mm: rename mm_put_huge_zero_page to mm_put_huge_zero_folio 2024-04-25 20:56:20 -07:00
hugetlb_cgroup.c mm, hugetlb: remove HUGETLB_CGROUP_MIN_ORDER 2023-10-18 14:34:17 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: move mmap lock to vmemmap_remap_range() 2023-12-12 10:57:08 -08:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: fix reference to nonexistent file 2023-10-25 16:47:14 -07:00
hugetlb.c mm/hugetlb: declare hugetlbfs_pagecache_present() non-static 2024-04-25 20:56:20 -07:00
hwpoison-inject.c
init-mm.c mm: Deprecate pasid field 2023-12-12 10:11:32 +01:00
internal.h mm: make page_mapped() take a const argument 2024-04-25 20:56:14 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
Kconfig mm/Kconfig: CONFIG_PGTABLE_HAS_HUGE_LEAVES 2024-04-25 20:56:20 -07:00
Kconfig.debug mm/slub: unify all sl[au]b parameters with "slab_$param" 2024-01-22 10:31:08 +01:00
khugepaged.c mm: convert free_swap_cache() to take a folio 2024-03-04 17:01:26 -08:00
kmemleak.c mm/kmemleak: compact kmemleak_object further 2024-04-25 20:56:05 -07:00
ksm.c mm: convert page_try_share_anon_rmap() to folio_try_share_anon_rmap_[pte|pmd]() 2023-12-29 11:58:56 -08:00
list_lru.c mm/zswap: stop lru list shrinking when encounter warm region 2024-02-22 10:24:54 -08:00
maccess.c
madvise.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
Makefile mm/kmemleak: disable KASAN instrumentation in kmemleak 2024-04-25 20:56:05 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
memcontrol.c mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
memfd.c mm/memfd: refactor memfd_tag_pins() and memfd_wait_for_pins() 2024-03-04 17:01:21 -08:00
memory_hotplug.c mm: record the migration reason for struct migration_target_control 2024-04-25 20:56:06 -07:00
memory-failure.c mm: record the migration reason for struct migration_target_control 2024-04-25 20:56:06 -07:00
memory-tiers.c mm/demotion: print demotion targets 2024-02-22 10:24:55 -08:00
memory.c mm: introduce vma_pgtable_walk_{begin|end}() 2024-04-25 20:56:21 -07:00
mempolicy.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mempool.c mempool: hook up to memory allocation profiling 2024-04-25 20:55:56 -07:00
memremap.c mm: remove stale example from comment 2023-12-29 11:58:26 -08:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-03-13 12:12:21 -07:00
migrate_device.c mm: convert migrate_vma_collect_pmd to use a folio 2024-04-25 20:56:19 -07:00
migrate.c remove references to page->flags in documentation 2024-04-25 20:56:15 -07:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mm_init.c mm/mm_init.c: remove the outdated code comment above deferred_grow_zone() 2024-04-25 20:56:17 -07:00
mm_slot.h
mmap_lock.c
mmap.c mm/mmap: convert all mas except mas_detach to vma iterator 2024-04-25 20:56:11 -07:00
mmu_gather.c mm/mmu_gather: improve cond_resched() handling with large folios and expensive page freeing 2024-02-22 15:27:17 -08:00
mmu_notifier.c mmu_notifiers: rename invalidate_range notifier 2023-08-18 10:12:41 -07:00
mmzone.c zswap: shrink zswap pool based on memory pressure 2023-12-12 10:57:02 -08:00
mprotect.c mprotect: use pfn_swap_entry_folio 2024-02-21 16:00:03 -08:00
mremap.c mm: abstract VMA merge and extend into vma_merge_extend() helper 2023-10-18 14:34:18 -07:00
msync.c
nommu.c mm: remove follow_pfn 2024-04-25 20:56:12 -07:00
oom_kill.c mm: update mark_victim tracepoints fields 2024-03-04 17:01:16 -08:00
page_alloc.c mm/page_alloc.c: change the array-length to MIGRATE_PCPTYPES 2024-04-25 20:56:18 -07:00
page_counter.c
page_ext.c mm: make page_ext_get() take a const argument 2024-04-25 20:56:14 -07:00
page_idle.c
page_io.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
page_isolation.c mm: page_isolation: prepare for hygienic freelists 2024-04-25 20:56:04 -07:00
page_owner.c mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
page_poison.c mm/page_poison: replace kmap_atomic() with kmap_local_page() 2023-12-10 16:51:50 -08:00
page_reporting.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
page_reporting.h
page_table_check.c mm: convert page_table_check_pte_set() to page_table_check_ptes_set() 2023-08-24 16:20:18 -07:00
page_vma_mapped.c mm: thp: introduce multi-size THP sysfs interface 2023-12-20 14:48:12 -08:00
page-writeback.c writeback: remove a use of write_cache_pages() from do_writepages() 2024-02-23 17:48:38 -08:00
pagewalk.c mm: pagewalk: assert write mmap lock only for walking the user page tables 2023-12-10 16:51:53 -08:00
percpu-internal.h mm: percpu: add codetag reference into pcpuobj_ext 2024-04-25 20:55:56 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c percpu: clean up all mappings when pcpu_map_pages() fails 2024-04-25 20:55:49 -07:00
percpu.c mm: percpu: enable per-cpu allocation tagging 2024-04-25 20:55:56 -07:00
pgalloc-track.h
pgtable-generic.c mm/pgtable: notes on pte_offset_map[_lock]() 2023-08-18 10:12:25 -07:00
process_vm_access.c mm: fix process_vm_rw page counts 2023-12-10 16:51:39 -08:00
ptdump.c mm: ptdump: add check_wx_pages debugfs attribute 2024-02-22 10:24:47 -08:00
readahead.c mm/readahead: break read-ahead loop if filemap_add_folio return -ENOMEM 2024-04-25 20:56:07 -07:00
rmap.c remove references to page->flags in documentation 2024-04-25 20:56:15 -07:00
rodata_test.c
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-03-26 11:07:23 -07:00
shmem.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
show_mem.c lib: add memory allocations report in show_mem() 2024-04-25 20:55:57 -07:00
shrinker_debug.c mm: shrinker: convert shrinker_rwsem to mutex 2023-10-04 10:32:26 -07:00
shrinker.c mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info() 2024-01-05 09:58:32 -08:00
shuffle.c
shuffle.h mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
slab_common.c mm/slab: enable slab allocation tagging for kmalloc and friends 2024-04-25 20:55:55 -07:00
slab.h mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
slub.c mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
sparse-vmemmap.c mm/vmemmap: allow architectures to override how vmemmap optimization works 2023-08-18 10:12:53 -07:00
sparse.c mm: move array mem_section init code out of memory_present() 2024-04-25 20:56:16 -07:00
swap_cgroup.c
swap_slots.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
swap_state.c mm: add is_huge_zero_folio() 2024-04-25 20:56:18 -07:00
swap.c mm: add is_huge_zero_folio() 2024-04-25 20:56:18 -07:00
swap.h mm/swap: fix race when skipping swapcache 2024-02-20 14:20:48 -08:00
swapfile.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
truncate.c fs: convert error_remove_page to error_remove_folio 2023-12-10 16:51:42 -08:00
usercopy.c
userfaultfd.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
util.c mm: vmalloc: enable memory allocation profiling 2024-04-25 20:55:57 -07:00
vmalloc.c mm/vmalloc.c: optimize to reduce arguments of alloc_vmap_area() 2024-04-25 20:56:08 -07:00
vmpressure.c eventfd: simplify eventfd_signal() 2023-11-28 14:08:38 +01:00
vmscan.c mm: hold PTL from the first PTE while reclaiming a large folio 2024-04-25 20:56:08 -07:00
vmstat.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
workingset.c mm: move mapping_set_update out of <linux/swap.h> 2024-02-21 11:36:50 +05:30
z3fold.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zbud.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zpool.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zsmalloc.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zswap.c zswap: replace RB tree with xarray 2024-04-25 20:56:18 -07:00