linux.git/fs/proc/task_mmu.c, branch v6.1

mm: /proc/pid/smaps_rollup: fix maple tree search

2022-10-21T04:27:23+00:00

/proc/pid/smaps_rollup showed 0 kB for everything: now find first vma.

Link: https://lkml.kernel.org/r/3011bee7-182-97a2-1083-d5f5b688e54b@google.com
Fixes: c4c84f06285e ("fs/proc/task_mmu: stop using linked list and highest_vm_end")
Signed-off-by: Hugh Dickins 
Reviewed-by: Liam R. Howlett 
Cc: Alexey Dobriyan 
Cc: Matthew Wilcox (Oracle) 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

fs/proc/task_mmu: stop using linked list and highest_vm_end

2022-09-27T02:46:21+00:00

Remove references to mm_struct linked list and highest_vm_end for when
they are removed

Link: https://lkml.kernel.org/r/20220906194824.2110408-44-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Liam R. Howlett 
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: remove vmacache

2022-09-27T02:46:18+00:00

By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code.  Remove the vmacache
to reduce the work in keeping it up to date and code complexity.

Link: https://lkml.kernel.org/r/20220906194824.2110408-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett 
Acked-by: Vlastimil Babka 
Tested-by: Yu Zhao 
Cc: Catalin Marinas 
Cc: David Hildenbrand 
Cc: David Howells 
Cc: Davidlohr Bueso 
Cc: "Matthew Wilcox (Oracle)" 
Cc: SeongJae Park 
Cc: Sven Schnelle 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

mm/swap: add swp_offset_pfn() to fetch PFN from swap entry

2022-09-27T02:46:05+00:00

We've got a bunch of special swap entries that stores PFN inside the swap
offset fields.  To fetch the PFN, normally the user just calls
swp_offset() assuming that'll be the PFN.

Add a helper swp_offset_pfn() to fetch the PFN instead, fetching only the
max possible length of a PFN on the host, meanwhile doing proper check
with MAX_PHYSMEM_BITS to make sure the swap offsets can actually store the
PFNs properly always using the BUILD_BUG_ON() in is_pfn_swap_entry().

One reason to do so is we never tried to sanitize whether swap offset can
really fit for storing PFN.  At the meantime, this patch also prepares us
with the future possibility to store more information inside the swp
offset field, so assuming "swp_offset(entry)" to be the PFN will not stand
any more very soon.

Replace many of the swp_offset() callers to use swp_offset_pfn() where
proper.  Note that many of the existing users are not candidates for the
replacement, e.g.:

  (1) When the swap entry is not a pfn swap entry at all, or,
  (2) when we wanna keep the whole swp_offset but only change the swp type.

For the latter, it can happen when fork() triggered on a write-migration
swap entry pte, we may want to only change the migration type from
write->read but keep the rest, so it's not "fetching PFN" but "changing
swap type only".  They're left aside so that when there're more
information within the swp offset they'll be carried over naturally in
those cases.

Since at it, dropping hwpoison_entry_to_pfn() because that's exactly what
the new swp_offset_pfn() is about.

Link: https://lkml.kernel.org/r/20220811161331.37055-4-peterx@redhat.com
Signed-off-by: Peter Xu 
Reviewed-by: "Huang, Ying" 
Cc: Alistair Popple 
Cc: Andi Kleen 
Cc: Andrea Arcangeli 
Cc: David Hildenbrand 
Cc: Hugh Dickins 
Cc: "Kirill A . Shutemov" 
Cc: Minchan Kim 
Cc: Nadav Amit 
Cc: Vlastimil Babka 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton

mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()

2022-09-12T03:25:45+00:00

MADV_COLLAPSE is not coupled to the kernel-oriented sysfs THP settings[1].

hugepage_vma_check() is the authority on determining if a VMA is eligible
for THP allocation/collapse, and currently enforces the sysfs THP
settings.  Add a flag to disable these checks.  For now, only apply this
arg to anon and file, which use /sys/kernel/transparent_hugepage/enabled. 
We can expand this to shmem, which uses
/sys/kernel/transparent_hugepage/shmem_enabled, later.

Use this flag in collapse_pte_mapped_thp() where previously the VMA flags
passed to hugepage_vma_check() were OR'd with VM_HUGEPAGE to elide the
VM_HUGEPAGE check in "madvise" THP mode.  Prior to "mm: khugepaged: check
THP flag in hugepage_vma_check()", this check also didn't check "never"
THP mode.  As such, this restores the previous behavior of
collapse_pte_mapped_thp() where sysfs THP settings are ignored.  See
comment in code for justification why this is OK.

[1] https://lore.kernel.org/linux-mm/CAAa6QmQxay1_=Pmt8oCX2-Va18t44FV-Vs-WsQt_6+qBks4nZA@mail.gmail.com/

Link: https://lkml.kernel.org/r/20220706235936.2197195-8-zokeefe@google.com
Signed-off-by: Zach O'Keefe 
Reviewed-by: Yang Shi 
Cc: Alex Shi 
Cc: Andrea Arcangeli 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Chris Kennelly 
Cc: Chris Zankel 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: Helge Deller 
Cc: Hugh Dickins 
Cc: Ivan Kokshaysky 
Cc: James Bottomley 
Cc: Jens Axboe 
Cc: "Kirill A. Shutemov" 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Minchan Kim 
Cc: Pasha Tatashin 
Cc: Pavel Begunkov 
Cc: Peter Xu 
Cc: Rongwei Wang 
Cc: SeongJae Park 
Cc: Song Liu 
Cc: Thomas Bogendoerfer 
Cc: Vlastimil Babka 
Cc: Zi Yan 
Cc: Dan Carpenter 
Cc: "Souptick Joarder (HPE)" 
Signed-off-by: Andrew Morton

mm/smaps: don't access young/dirty bit if pte unpresent

2022-08-20T22:17:45+00:00

These bits should only be valid when the ptes are present.  Introducing
two booleans for it and set it to false when !pte_present() for both pte
and pmd accountings.

The bug is found during code reading and no real world issue reported, but
logically such an error can cause incorrect readings for either smaps or
smaps_rollup output on quite a few fields.

For example, it could cause over-estimate on values like Shared_Dirty,
Private_Dirty, Referenced.  Or it could also cause under-estimate on
values like LazyFree, Shared_Clean, Private_Clean.

Link: https://lkml.kernel.org/r/20220805160003.58929-1-peterx@redhat.com
Fixes: b1d4d9e0cbd0 ("proc/smaps: carefully handle migration entries")
Fixes: c94b6923fa0a ("/proc/PID/smaps: Add PMD migration entry parsing")
Signed-off-by: Peter Xu 
Reviewed-by: Vlastimil Babka 
Reviewed-by: David Hildenbrand 
Reviewed-by: Yang Shi 
Cc: Konstantin Khlebnikov 
Cc: Huang Ying 
Signed-off-by: Andrew Morton

mm: thp: kill __transhuge_page_enabled()

2022-07-18T00:14:33+00:00

The page fault path checks THP eligibility with __transhuge_page_enabled()
which does the similar thing as hugepage_vma_check(), so use
hugepage_vma_check() instead.

However page fault allows DAX and !anon_vma cases, so added a new flag,
in_pf, to hugepage_vma_check() to make page fault work correctly.

The in_pf flag is also used to skip shmem and file THP for page fault
since shmem handles THP in its own shmem_fault() and file THP allocation
on fault is not supported yet.

Also remove hugepage_vma_enabled() since hugepage_vma_check() is the only
caller now, it is not necessary to have a helper function.

Link: https://lkml.kernel.org/r/20220616174840.1202070-6-shy828301@gmail.com
Signed-off-by: Yang Shi 
Reviewed-by: Zach O'Keefe 
Cc: Kirill A. Shutemov 
Cc: Matthew Wilcox 
Cc: Miaohe Lin 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

mm: thp: kill transparent_hugepage_active()

2022-07-18T00:14:33+00:00

The transparent_hugepage_active() was introduced to show THP eligibility
bit in smaps in proc, smaps is the only user.  But it actually does the
similar check as hugepage_vma_check() which is used by khugepaged.  We
definitely don't have to maintain two similar checks, so kill
transparent_hugepage_active().

This patch also fixed the wrong behavior for VM_NO_KHUGEPAGED vmas.

Also move hugepage_vma_check() to huge_memory.c and huge_mm.h since it
is not only for khugepaged anymore.

[akpm@linux-foundation.org: check vma->vm_mm, per Zach]
[akpm@linux-foundation.org: add comment to vdso check]
Link: https://lkml.kernel.org/r/20220616174840.1202070-5-shy828301@gmail.com
Signed-off-by: Yang Shi 
Reviewed-by: Zach O'Keefe 
Cc: Kirill A. Shutemov 
Cc: Matthew Wilcox 
Cc: Miaohe Lin 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

mm: handling Non-LRU pages returned by vm_normal_pages

2022-07-18T00:14:28+00:00

With DEVICE_COHERENT, we'll soon have vm_normal_pages() return
device-managed anonymous pages that are not LRU pages.  Although they
behave like normal pages for purposes of mapping in CPU page, and for COW.
They do not support LRU lists, NUMA migration or THP.

Callers to follow_page() currently don't expect ZONE_DEVICE pages,
however, with DEVICE_COHERENT we might now return ZONE_DEVICE.  Check for
ZONE_DEVICE pages in applicable users of follow_page() as well.

Link: https://lkml.kernel.org/r/20220715150521.18165-5-alex.sierra@amd.com
Signed-off-by: Alex Sierra 
Acked-by: Felix Kuehling 	[v2]
Reviewed-by: Alistair Popple 	[v6]
Cc: Christoph Hellwig 
Cc: David Hildenbrand 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: Matthew Wilcox 
Cc: Ralph Campbell 
Signed-off-by: Andrew Morton

mm/smaps: add Pss_Dirty

2022-07-04T01:08:49+00:00

Pss is the sum of the sizes of clean and dirty private pages, and the
proportional sizes of clean and dirty shared pages:

 Private = Private_Dirty + Private_Clean
 Shared_Proportional = Shared_Dirty_Proportional + Shared_Clean_Proportional
 Pss = Private + Shared_Proportional

The Shared*Proportional fields are not present in smaps, so it is not
always possible to determine how much of the Pss is from dirty pages and
how much is from clean pages.  This information can be useful for
measuring memory usage for the purpose of optimisation, since clean pages
can usually be discarded by the kernel immediately while dirty pages
cannot.

The smaps routines in the kernel already have access to this data, so add
a Pss_Dirty to show it to userspace.  Pss_Clean is not added since it can
be calculated from Pss and Pss_Dirty.

Link: https://lkml.kernel.org/r/20220620081251.2928103-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch 
Cc: Jonathan Corbet 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton