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We already have newline in TP_printk so remove the redundant newline
character at the end of the mmap trace.
<...>-345 [006] ..... 95.589290: exit_mmap: mt_mod ...
<...>-345 [006] ..... 95.589413: vm_unmapped_area: addr=...
<...>-345 [006] ..... 95.589571: vm_unmapped_area: addr=...
<...>-345 [006] ..... 95.589606: vm_unmapped_area: addr=...
to
<...>-336 [006] ..... 44.762506: exit_mmap: mt_mod ...
<...>-336 [006] ..... 44.762654: vm_unmapped_area: addr=...
<...>-336 [006] ..... 44.762794: vm_unmapped_area: addr=...
<...>-336 [006] ..... 44.762835: vm_unmapped_area: addr=...
Link: https://lkml.kernel.org/r/ZAu6qDsNPmk82UjV@minwoo-desktop
FIxes: df529cabb7a25 ("mm: mmap: add trace point of vm_unmapped_area")
Signed-off-by: Minwoo Im <[email protected]>
Acked-by: Steven Rostedt (Google) <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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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/[email protected]
Signed-off-by: Liam R. Howlett <[email protected]>
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Tested-by: Yu Zhao <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Howells <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Even on 64 bit kernel, the mmap failure can happen for a 32 bit task.
Virtual memory space shortage of a task on mmap is reported to userspace
as -ENOMEM. It can be confused as physical memory shortage of overall
system.
The vm_unmapped_area can be called to by some drivers or other kernel core
system like filesystem. In my platform, GPU driver calls to
vm_unmapped_area and the driver returns -ENOMEM even in GPU side shortage.
It can be hard to distinguish which code layer returns the -ENOMEM.
Create mmap trace file and add trace point of vm_unmapped_area.
i.e.)
277.156599: vm_unmapped_area: addr=77e0d03000 err=0 total_vm=0x17014b flags=0x1 len=0x400000 lo=0x8000 hi=0x7878c27000 mask=0x0 ofs=0x1
342.838740: vm_unmapped_area: addr=0 err=-12 total_vm=0xffb08 flags=0x0 len=0x100000 lo=0x40000000 hi=0xfffff000 mask=0x0 ofs=0x22
[[email protected]: prefix address printk with 0x, per Matthew]
Signed-off-by: Jaewon Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
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