linux.git/mm/memory_hotplug.c, branch v5.4-rc2

mm/memory_hotplug.c: s/is/if

2019-09-24T22:54:09+00:00

Correct typo in comment.

Link: http://lkml.kernel.org/r/1568233954-3913-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder 
Reviewed-by: Andrew Morton 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: online_pages cannot be 0 in online_pages()

2019-09-24T22:54:09+00:00

walk_system_ram_range() will fail with -EINVAL in case
online_pages_range() was never called (== no resource applicable in the
range).  Otherwise, we will always call online_pages_range() with nr_pages
> 0 and, therefore, have online_pages > 0.

Remove that special handling.

Link: http://lkml.kernel.org/r/20190814154109.3448-6-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Oscar Salvador 
Cc: Michal Hocko 
Cc: Pavel Tatashin 
Cc: Dan Williams 
Cc: Arun KS 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Ingo Molnar 
Cc: Nadav Amit 
Cc: Wei Yang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: make sure the pfn is aligned to the order when onlining

2019-09-24T22:54:09+00:00

Commit a9cd410a3d29 ("mm/page_alloc.c: memory hotplug: free pages as
higher order") assumed that any PFN we get via memory resources is aligned
to to MAX_ORDER - 1, I am not convinced that is always true.  Let's play
safe, check the alignment and fallback to single pages.

akpm: warn in this situation so we get to find out if and why this ever
occurs.

[akpm@linux-foundation.org: add WARN_ON_ONCE()]
Link: http://lkml.kernel.org/r/20190814154109.3448-5-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Arun KS 
Cc: Oscar Salvador 
Cc: Michal Hocko 
Cc: Pavel Tatashin 
Cc: Dan Williams 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Ingo Molnar 
Cc: Nadav Amit 
Cc: Wei Yang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: simplify online_pages_range()

2019-09-24T22:54:09+00:00

online_pages always corresponds to nr_pages.  Simplify the code, getting
rid of online_pages_blocks().  Add some comments.

Link: http://lkml.kernel.org/r/20190814154109.3448-4-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Oscar Salvador 
Cc: Pavel Tatashin 
Cc: Dan Williams 
Cc: Arun KS 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Ingo Molnar 
Cc: Nadav Amit 
Cc: Wei Yang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: drop PageReserved() check in online_pages_range()

2019-09-24T22:54:09+00:00

move_pfn_range_to_zone() will set all pages to PG_reserved via
memmap_init_zone().  The only way a page could no longer be reserved would
be if a MEM_GOING_ONLINE notifier would clear PG_reserved - which is not
done (the online_page callback is used for that purpose by e.g., Hyper-V
instead).  walk_system_ram_range() will never call online_pages_range()
with duplicate PFNs, so drop the PageReserved() check.

This seems to be a leftover from ancient times where the memmap was
initialized when adding memory and we wanted to check for already onlined
memory.

Link: http://lkml.kernel.org/r/20190814154109.3448-3-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Oscar Salvador 
Cc: Pavel Tatashin 
Cc: Dan Williams 
Cc: Arun KS 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Ingo Molnar 
Cc: Nadav Amit 
Cc: Wei Yang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: prevent memory leak when reusing pgdat

2019-09-24T22:54:09+00:00

When offlining a node in try_offline_node(), pgdat is not released.  So
that pgdat could be reused in hotadd_new_pgdat().  While we reallocate
pgdat->per_cpu_nodestats if this pgdat is reused.

This patch prevents the memory leak by just allocating per_cpu_nodestats
when it is a new pgdat.

Link: http://lkml.kernel.org/r/20190813020608.10194-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang 
Acked-by: Michal Hocko 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/base/memory.c: don't store end_section_nr in memory blocks

2019-09-24T22:54:09+00:00

Each memory block spans the same amount of sections/pages/bytes.  The size
is determined before the first memory block is created.  No need to store
what we can easily calculate - and the calculations even look simpler now.

Michal brought up the idea of variable-sized memory blocks.  However, if
we ever implement something like this, we will need an API compatibility
switch and reworks at various places (most code assumes a fixed memory
block size).  So let's cleanup what we have right now.

While at it, fix the variable naming in register_mem_sect_under_node() -
we no longer talk about a single section.

Link: http://lkml.kernel.org/r/20190809110200.2746-1-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Pavel Tatashin 
Cc: Michal Hocko 
Cc: Dan Williams 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: remove move_pfn_range()

2019-09-24T22:54:09+00:00

Let's remove this indirection.  We need the zone in the caller either way,
so let's just detect it there.  Add some documentation for
move_pfn_range_to_zone() instead.

[akpm@linux-foundation.org: restore newline, per David]
Link: http://lkml.kernel.org/r/20190724142324.3686-1-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Reviewed-by: Oscar Salvador 
Cc: David Hildenbrand 
Cc: Pavel Tatashin 
Cc: Dan Williams 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce compound_nr()

2019-09-24T22:54:08+00:00

Replace 1 << compound_order(page) with compound_nr(page).  Minor
improvements in readability.

Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Andrew Morton 
Reviewed-by: Ira Weiny 
Acked-by: Kirill A. Shutemov 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: remove unneeded return for void function

2019-08-03T14:02:01+00:00

return is unneeded in void function

Link: http://lkml.kernel.org/r/20190723130814.21826-1-houweitaoo@gmail.com
Signed-off-by: Weitao Hou 
Reviewed-by: David Hildenbrand 
Reviewed-by: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds