linux-stable.git/mm/sparse.c, branch linux-5.0.y

mm/sparse: fix a bad comparison

2019-04-05T20:34:22+00:00

[ Upstream commit d778015ac95bc036af73342c878ab19250e01fe1 ]

next_present_section_nr() could only return an unsigned number -1, so
just check it specifically where compilers will convert -1 to unsigned
if needed.

  mm/sparse.c: In function 'sparse_init_nid':
  mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
         ((section_nr >= 0) &&    \
                      ^~
  mm/sparse.c:478:2: note: in expansion of macro
  'for_each_present_section_nr'
    for_each_present_section_nr(pnum_begin, pnum) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
         ((section_nr >= 0) &&    \
                      ^~
  mm/sparse.c:497:2: note: in expansion of macro
  'for_each_present_section_nr'
    for_each_present_section_nr(pnum_begin, pnum) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  mm/sparse.c: In function 'sparse_init':
  mm/sparse.c:200:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
         ((section_nr >= 0) &&    \
                      ^~
  mm/sparse.c:520:2: note: in expansion of macro
  'for_each_present_section_nr'
    for_each_present_section_nr(pnum_begin + 1, pnum_end) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~

Link: http://lkml.kernel.org/r/20190228181839.86504-1-cai@lca.pw
Fixes: c4e1be9ec113 ("mm, sparsemem: break out of loops early")
Signed-off-by: Qian Cai 
Reviewed-by: Andrew Morton 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

mm/hotplug: fix offline undo_isolate_page_range()

2019-04-03T04:27:36+00:00

commit 9b7ea46a82b31c74a37e6ff1c2a1df7d53e392ab upstream.

Commit f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded
memory to zones until online") introduced move_pfn_range_to_zone() which
calls memmap_init_zone() during onlining a memory block.
memmap_init_zone() will reset pagetype flags and makes migrate type to
be MOVABLE.

However, in __offline_pages(), it also call undo_isolate_page_range()
after offline_isolated_pages() to do the same thing.  Due to commit
2ce13640b3f4 ("mm: __first_valid_page skip over offline pages") changed
__first_valid_page() to skip offline pages, undo_isolate_page_range()
here just waste CPU cycles looping around the offlining PFN range while
doing nothing, because __first_valid_page() will return NULL as
offline_isolated_pages() has already marked all memory sections within
the pfn range as offline via offline_mem_sections().

Also, after calling the "useless" undo_isolate_page_range() here, it
reaches the point of no returning by notifying MEM_OFFLINE.  Those pages
will be marked as MIGRATE_MOVABLE again once onlining.  The only thing
left to do is to decrease the number of isolated pageblocks zone counter
which would make some paths of the page allocation slower that the above
commit introduced.

Even if alloc_contig_range() can be used to isolate 16GB-hugetlb pages
on ppc64, an "int" should still be enough to represent the number of
pageblocks there.  Fix an incorrect comment along the way.

[cai@lca.pw: v4]
  Link: http://lkml.kernel.org/r/20190314150641.59358-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190313143133.46200-1-cai@lca.pw
Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages")
Signed-off-by: Qian Cai 
Acked-by: Michal Hocko 
Reviewed-by: Oscar Salvador 
Cc: Vlastimil Babka 
Cc: 	[4.13+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm, sparse: pass nid instead of pgdat to sparse_add_one_section()

2018-12-28T20:11:49+00:00

Since the information needed in sparse_add_one_section() is node id to
allocate proper memory, it is not necessary to pass its pgdat.

This patch changes the prototype of sparse_add_one_section() to pass node
id directly.  This is intended to reduce misleading that
sparse_add_one_section() would touch pgdat.

Link: http://lkml.kernel.org/r/20181204085657.20472-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang 
Reviewed-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Dave Hansen 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, sparse: drop pgdat_resize_lock in sparse_add/remove_one_section()

2018-12-28T20:11:49+00:00

pgdat_resize_lock is used to protect pgdat's memory region information
like: node_start_pfn, node_present_pages, etc.  While in function
sparse_add/remove_one_section(), pgdat_resize_lock is used to protect
initialization/release of one mem_section.  This looks not proper.

These code paths are currently protected by mem_hotplug_lock currently but
should there ever be any reason for locking at the sparse layer a
dedicated lock should be introduced.

Following is the current call trace of sparse_add/remove_one_section()

    mem_hotplug_begin()
    arch_add_memory()
       add_pages()
           __add_pages()
               __add_section()
                   sparse_add_one_section()
    mem_hotplug_done()

    mem_hotplug_begin()
    arch_remove_memory()
        __remove_pages()
            __remove_section()
                sparse_remove_one_section()
    mem_hotplug_done()

The comment above the pgdat_resize_lock also mentions "Holding this will
also guarantee that any pfn_valid() stays that way.", which is true with
the current implementation and false after this patch.  But current
implementation doesn't meet this comment.  There isn't any pfn walkers to
take the lock so this looks like a relict from the past.  This patch also
removes this comment.

[richard.weiyang@gmail.com: v4]
  Link: http://lkml.kernel.org/r/20181204085657.20472-1-richard.weiyang@gmail.com
[mhocko@suse.com: changelog suggestion]
Link: http://lkml.kernel.org/r/20181128091243.19249-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang 
Reviewed-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Dave Hansen 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hotplug: optimize clear_hwpoisoned_pages()

2018-12-28T20:11:46+00:00

In hot remove, we try to clear poisoned pages, but a small optimization to
check if num_poisoned_pages is 0 helps remove the iteration through
nr_pages.

[akpm@linux-foundation.org: tweak comment text]
Link: http://lkml.kernel.org/r/20181102120001.4526-1-bsingharora@gmail.com
Signed-off-by: Balbir Singh 
Acked-by: Michal Hocko 
Acked-by: Naoya Horiguchi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/sparse: add common helper to mark all memblocks present

2018-12-14T23:05:45+00:00

Presently the arches arm64, arm and sh have a function which loops
through each memblock and calls memory present.  riscv will require a
similar function.

Introduce a common memblocks_present() function that can be used by all
the arches.  Subsequent patches will cleanup the arches that make use of
this.

Link: http://lkml.kernel.org/r/20181107205433.3875-3-logang@deltatee.com
Signed-off-by: Logan Gunthorpe 
Acked-by: Andrew Morton 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: stop using implicit alignment to SMP_CACHE_BYTES

2018-10-31T15:54:16+00:00

When a memblock allocation APIs are called with align = 0, the alignment
is implicitly set to SMP_CACHE_BYTES.

Implicit alignment is done deep in the memblock allocator and it can
come as a surprise.  Not that such an alignment would be wrong even
when used incorrectly but it is better to be explicit for the sake of
clarity and the prinicple of the least surprise.

Replace all such uses of memblock APIs with the 'align' parameter
explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment
in the memblock internal allocation functions.

For the case when memblock APIs are used via helper functions, e.g.  like
iommu_arena_new_node() in Alpha, the helper functions were detected with
Coccinelle's help and then manually examined and updated where
appropriate.

The direct memblock APIs users were updated using the semantic patch below:

@@
expression size, min_addr, max_addr, nid;
@@
(
|
- memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid)
|
- memblock_alloc(size, 0)
+ memblock_alloc(size, SMP_CACHE_BYTES)
|
- memblock_alloc_raw(size, 0)
+ memblock_alloc_raw(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from(size, 0, min_addr)
+ memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_nopanic(size, 0)
+ memblock_alloc_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low(size, 0)
+ memblock_alloc_low(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low_nopanic(size, 0)
+ memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from_nopanic(size, 0, min_addr)
+ memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_node(size, 0, nid)
+ memblock_alloc_node(size, SMP_CACHE_BYTES, nid)
)

[mhocko@suse.com: changelog update]
[akpm@linux-foundation.org: coding-style fixes]
[rppt@linux.ibm.com: fix missed uses of implicit alignment]
  Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx
Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Suggested-by: Michal Hocko 
Acked-by: Paul Burton 	[MIPS]
Acked-by: Michael Ellerman 	[powerpc]
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: Geert Uytterhoeven 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: Matt Turner 
Cc: Michal Simek 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove include/linux/bootmem.h

2018-10-31T15:54:16+00:00

Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include 

@@
@@
- #include 
+ #include 

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
  Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Signed-off-by: Stephen Rothwell 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: replace BOOTMEM_ALLOC_* with MEMBLOCK variants

2018-10-31T15:54:16+00:00

Drop BOOTMEM_ALLOC_ACCESSIBLE and BOOTMEM_ALLOC_ANYWHERE in favor of
identical MEMBLOCK definitions.

Link: http://lkml.kernel.org/r/1536927045-23536-29-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: add align parameter to memblock_alloc_node()

2018-10-31T15:54:15+00:00

With the align parameter memblock_alloc_node() can be used as drop in
replacement for alloc_bootmem_pages_node() and __alloc_bootmem_node(),
which is done in the following patches.

Link: http://lkml.kernel.org/r/1536927045-23536-15-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds