linux.git/include/trace/events/mmap.h, branch vsnprintf

mm: mmap: remove newline at the end of the trace

2023-03-24T00:18:36+00:00

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 
Acked-by: Steven Rostedt (Google) 
Reviewed-by: Mukesh Ojha 
Reviewed-by: David Hildenbrand 
Signed-off-by: Andrew Morton

mm: start tracking VMAs with maple tree

2022-09-27T02:46:14+00:00

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 
Signed-off-by: Matthew Wilcox (Oracle) 
Tested-by: Yu Zhao 
Cc: Catalin Marinas 
Cc: David Hildenbrand 
Cc: David Howells 
Cc: Davidlohr Bueso 
Cc: SeongJae Park 
Cc: Sven Schnelle 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

mm: mmap: add trace point of vm_unmapped_area

2020-04-02T16:35:30+00:00

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

[akpm@linux-foundation.org: prefix address printk with 0x, per Matthew]
Signed-off-by: Jaewon Kim 
Signed-off-by: Andrew Morton 
Cc: Borislav Petkov 
Cc: Matthew Wilcox (Oracle) 
Cc: Michel Lespinasse 
Cc: Vlastimil Babka 
Link: http://lkml.kernel.org/r/20200320055823.27089-3-jaewon31.kim@samsung.com
Signed-off-by: Linus Torvalds