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authorLiam R. Howlett <Liam.Howlett@Oracle.com>2022-09-06 19:48:45 +0000
committerAndrew Morton <akpm@linux-foundation.org>2022-09-26 19:46:14 -0700
commitd4af56c5c7c6781ca6ca8075e2cf5bc119ed33d1 (patch)
treee3c5b2600a2a9231ab6bbb85ede7b2be92f637f9 /mm/nommu.c
parente15e06a8392321a19d8ebdbdd7643b7fa8874c17 (diff)
mm: start tracking VMAs with maple tree
Start tracking the VMAs with the new maple tree structure in parallel with the rb_tree. Add debug and trace events for maple tree operations and duplicate the rb_tree that is created on forks into the maple tree. The maple tree is added to the mm_struct including the mm_init struct, added support in required mm/mmap functions, added tracking in kernel/fork for process forking, and used to find the unmapped_area and checked against what the rbtree finds. This also moves the mmap_lock() in exit_mmap() since the oom reaper call does walk the VMAs. Otherwise lockdep will be unhappy if oom happens. When splitting a vma fails due to allocations of the maple tree nodes, the error path in __split_vma() calls new->vm_ops->close(new). The page accounting for hugetlb is actually in the close() operation, so it accounts for the removal of 1/2 of the VMA which was not adjusted. This results in a negative exit value. To avoid the negative charge, set vm_start = vm_end and vm_pgoff = 0. There is also a potential accounting issue in special mappings from insert_vm_struct() failing to allocate, so reverse the charge there in the failure scenario. Link: https://lkml.kernel.org/r/20220906194824.2110408-9-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/nommu.c')
-rw-r--r--mm/nommu.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index e819cbc21b39..c63793c53a82 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -545,6 +545,19 @@ static void put_nommu_region(struct vm_region *region)
__put_nommu_region(region);
}
+void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
+{
+ mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
+ mas_store_prealloc(mas, vma);
+}
+
+void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
+{
+ mas->index = vma->vm_start;
+ mas->last = vma->vm_end - 1;
+ mas_store_prealloc(mas, NULL);
+}
+
/*
* add a VMA into a process's mm_struct in the appropriate place in the list
* and tree and add to the address space's page tree also if not an anonymous