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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 04:09:35 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 04:09:35 +0300
commit3822a7c40997dc86b1458766a3f146d62393f084 (patch)
tree4473720ecbfaabeedfe58484425be77d0f89f736 /Documentation/mm/hugetlbfs_reserv.rst
parente4bc15889506723d7b93c053ad4a75cd58248d74 (diff)
parentf9366f4c2a29d14f5992b195e268240c2deb116e (diff)
downloadlinux-3822a7c40997dc86b1458766a3f146d62393f084.tar.xz
Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
Diffstat (limited to 'Documentation/mm/hugetlbfs_reserv.rst')
-rw-r--r--Documentation/mm/hugetlbfs_reserv.rst21
1 files changed, 11 insertions, 10 deletions
diff --git a/Documentation/mm/hugetlbfs_reserv.rst b/Documentation/mm/hugetlbfs_reserv.rst
index 05a44760da32..3d05d64de9b4 100644
--- a/Documentation/mm/hugetlbfs_reserv.rst
+++ b/Documentation/mm/hugetlbfs_reserv.rst
@@ -179,14 +179,14 @@ Consuming Reservations/Allocating a Huge Page
Reservations are consumed when huge pages associated with the reservations
are allocated and instantiated in the corresponding mapping. The allocation
-is performed within the routine alloc_huge_page()::
+is performed within the routine alloc_hugetlb_folio()::
- struct page *alloc_huge_page(struct vm_area_struct *vma,
+ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
unsigned long addr, int avoid_reserve)
-alloc_huge_page is passed a VMA pointer and a virtual address, so it can
+alloc_hugetlb_folio is passed a VMA pointer and a virtual address, so it can
consult the reservation map to determine if a reservation exists. In addition,
-alloc_huge_page takes the argument avoid_reserve which indicates reserves
+alloc_hugetlb_folio takes the argument avoid_reserve which indicates reserves
should not be used even if it appears they have been set aside for the
specified address. The avoid_reserve argument is most often used in the case
of Copy on Write and Page Migration where additional copies of an existing
@@ -206,7 +206,8 @@ a reservation for the allocation. After determining whether a reservation
exists and can be used for the allocation, the routine dequeue_huge_page_vma()
is called. This routine takes two arguments related to reservations:
-- avoid_reserve, this is the same value/argument passed to alloc_huge_page()
+- avoid_reserve, this is the same value/argument passed to
+ alloc_hugetlb_folio().
- chg, even though this argument is of type long only the values 0 or 1 are
passed to dequeue_huge_page_vma. If the value is 0, it indicates a
reservation exists (see the section "Memory Policy and Reservations" for
@@ -231,9 +232,9 @@ the scope reservations. Even if a surplus page is allocated, the same
reservation based adjustments as above will be made: SetPagePrivate(page) and
resv_huge_pages--.
-After obtaining a new huge page, (page)->private is set to the value of
-the subpool associated with the page if it exists. This will be used for
-subpool accounting when the page is freed.
+After obtaining a new hugetlb folio, (folio)->_hugetlb_subpool is set to the
+value of the subpool associated with the page if it exists. This will be used
+for subpool accounting when the folio is freed.
The routine vma_commit_reservation() is then called to adjust the reserve
map based on the consumption of the reservation. In general, this involves
@@ -244,8 +245,8 @@ was no reservation in a shared mapping or this was a private mapping a new
entry must be created.
It is possible that the reserve map could have been changed between the call
-to vma_needs_reservation() at the beginning of alloc_huge_page() and the
-call to vma_commit_reservation() after the page was allocated. This would
+to vma_needs_reservation() at the beginning of alloc_hugetlb_folio() and the
+call to vma_commit_reservation() after the folio was allocated. This would
be possible if hugetlb_reserve_pages was called for the same page in a shared
mapping. In such cases, the reservation count and subpool free page count
will be off by one. This rare condition can be identified by comparing the