linux.git/drivers/base/node.c, branch v4.19.115

drivers/base/node.c: simplify unregister_memory_block_under_nodes()

2020-01-29T15:43:26+00:00

commit d84f2f5a755208da3f93e17714631485cb3da11c upstream.

We don't allow to offline memory block devices that belong to multiple
numa nodes.  Therefore, such devices can never get removed.  It is
sufficient to process a single node when removing the memory block.  No
need to iterate over each and every PFN.

We already have the nid stored for each memory block.  Make sure that the
nid always has a sane value.

Please note that checking for node_online(nid) is not required.  If we
would have a memory block belonging to a node that is no longer offline,
then we would have a BUG in the node offlining code.

Link: http://lkml.kernel.org/r/20190719135244.15242-1-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: David Hildenbrand 
Cc: Stephen Rothwell 
Cc: Pavel Tatashin 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: David Hildenbrand 
Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail

2020-01-29T15:43:26+00:00

commit a31b264c2b415b29660da0bc2ba291a98629ce51 upstream.

We really don't want anything during memory hotunplug to fail.  We
always pass a valid memory block device, that check can go.  Avoid
allocating memory and eventually failing.  As we are always called under
lock, we can use a static piece of memory.  This avoids having to put
the structure onto the stack, having to guess about the stack size of
callers.

Patch inspired by a patch from Oscar Salvador.

In the future, there might be no need to iterate over nodes at all.
mem->nid should tell us exactly what to remove.  Memory block devices
with mixed nodes (added during boot) should properly fenced off and
never removed.

Link: http://lkml.kernel.org/r/20190527111152.16324-11-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Wei Yang 
Reviewed-by: Oscar Salvador 
Acked-by: Michal Hocko 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Alex Deucher 
Cc: "David S. Miller" 
Cc: Mark Brown 
Cc: Chris Wilson 
Cc: David Hildenbrand 
Cc: Jonathan Cameron 
Cc: Andrew Banman 
Cc: Andy Lutomirski 
Cc: Anshuman Khandual 
Cc: Ard Biesheuvel 
Cc: Arun KS 
Cc: Baoquan He 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Chintan Pandya 
Cc: Christophe Leroy 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Cc: Jun Yao 
Cc: "Kirill A. Shutemov" 
Cc: Logan Gunthorpe 
Cc: Mark Rutland 
Cc: Masahiro Yamada 
Cc: Mathieu Malaterre 
Cc: Michael Ellerman 
Cc: Mike Rapoport 
Cc: "mike.travis@hpe.com" 
Cc: Nicholas Piggin 
Cc: Paul Mackerras 
Cc: Pavel Tatashin 
Cc: Peter Zijlstra 
Cc: Qian Cai 
Cc: Rich Felker 
Cc: Rob Herring 
Cc: Robin Murphy 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vasily Gorbik 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: David Hildenbrand 
Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug: remove memory block devices before arch_remove_memory()

2020-01-29T15:43:26+00:00

commit 4c4b7f9ba9486c565aead99a198ceeef73ae81f6 upstream.

Let's factor out removing of memory block devices, which is only
necessary for memory added via add_memory() and friends that created
memory block devices.  Remove the devices before calling
arch_remove_memory().

This finishes factoring out memory block device handling from
arch_add_memory() and arch_remove_memory().

Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Dan Williams 
Acked-by: Michal Hocko 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: David Hildenbrand 
Cc: "mike.travis@hpe.com" 
Cc: Andrew Banman 
Cc: Ingo Molnar 
Cc: Alex Deucher 
Cc: "David S. Miller" 
Cc: Mark Brown 
Cc: Chris Wilson 
Cc: Oscar Salvador 
Cc: Jonathan Cameron 
Cc: Arun KS 
Cc: Mathieu Malaterre 
Cc: Andy Lutomirski 
Cc: Anshuman Khandual 
Cc: Ard Biesheuvel 
Cc: Baoquan He 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Chintan Pandya 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Joonsoo Kim 
Cc: Jun Yao 
Cc: "Kirill A. Shutemov" 
Cc: Logan Gunthorpe 
Cc: Mark Rutland 
Cc: Masahiro Yamada 
Cc: Michael Ellerman 
Cc: Mike Rapoport 
Cc: Nicholas Piggin 
Cc: Oscar Salvador 
Cc: Paul Mackerras 
Cc: Pavel Tatashin 
Cc: Peter Zijlstra 
Cc: Qian Cai 
Cc: Rich Felker 
Cc: Rob Herring 
Cc: Robin Murphy 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vasily Gorbik 
Cc: Wei Yang 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: David Hildenbrand 
Signed-off-by: Greg Kroah-Hartman

mm: hide incomplete nr_indirectly_reclaimable in sysfs

2019-04-20T07:16:05+00:00

In upstream branch this fixed by commit b29940c1abd7 ("mm: rename and
change semantics of nr_indirectly_reclaimable_bytes").

This fixes /sys/devices/system/node/node*/vmstat format:

...
nr_dirtied 6613155
nr_written 5796802
 11089216
...

Cc:  # 4.19.y
Fixes: 7aaf77272358 ("mm: don't show nr_indirectly_reclaimable in /proc/vmstat")
Signed-off-by: Konstantin Khlebnikov 
Cc: Roman Gushchin 
Cc: Vlastimil Babka 
Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug.c: drop unnecessary checks from register_mem_sect_under_node()

2018-08-17T23:20:29+00:00

Callers of register_mem_sect_under_node() are always passing a valid
memory_block (not NULL), so we can safely drop the check for NULL.

In the same way, register_mem_sect_under_node() is only called in case
the node is online, so we can safely remove that check as well.

Link: http://lkml.kernel.org/r/20180622111839.10071-5-osalvador@techadventures.net
Signed-off-by: Oscar Salvador 
Reviewed-by: Pavel Tatashin 
Tested-by: Reza Arbab 
Tested-by: Jonathan Cameron 
Cc: Pasha Tatashin 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()

2018-08-17T23:20:29+00:00

link_mem_sections() and walk_memory_range() share most of the code, so
we can use convert link_mem_sections() into a dummy function that calls
walk_memory_range() with a callback to register_mem_sect_under_node().

This patch converts register_mem_sect_under_node() in order to match a
walk_memory_range's callback, getting rid of the check_nid argument and
checking instead if the system is still boothing, since we only have to
check for the nid if the system is in such state.

Link: http://lkml.kernel.org/r/20180622111839.10071-4-osalvador@techadventures.net
Signed-off-by: Oscar Salvador 
Suggested-by: Pavel Tatashin 
Tested-by: Reza Arbab 
Tested-by: Jonathan Cameron 
Reviewed-by: Pavel Tatashin 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: fix leftover use of struct page during hotplug

2018-05-26T01:12:11+00:00

The case of a new numa node got missed in avoiding using the node info
from page_struct during hotplug.  In this path we have a call to
register_mem_sect_under_node (which allows us to specify it is hotplug
so don't change the node), via link_mem_sections which unfortunately
does not.

Fix is to pass check_nid through link_mem_sections as well and disable
it in the new numa node path.

Note the bug only 'sometimes' manifests depending on what happens to be
in the struct page structures - there are lots of them and it only needs
to match one of them.

The result of the bug is that (with a new memory only node) we never
successfully call register_mem_sect_under_node so don't get the memory
associated with the node in sysfs and meminfo for the node doesn't
report it.

It came up whilst testing some arm64 hotplug patches, but appears to be
universal.  Whilst I'm triggering it by removing then reinserting memory
to a node with no other elements (thus making the node disappear then
appear again), it appears it would happen on hotplugging memory where
there was none before and it doesn't seem to be related the arm64
patches.

These patches call __add_pages (where most of the issue was fixed by
Pavel's patch).  If there is a node at the time of the __add_pages call
then all is well as it calls register_mem_sect_under_node from there
with check_nid set to false.  Without a node that function returns
having not done the sysfs related stuff as there is no node to use.
This is expected but it is the resulting path that fails...

Exact path to the problem is as follows:

 mm/memory_hotplug.c: add_memory_resource()

   The node is not online so we enter the 'if (new_node)' twice, on the
   second such block there is a call to link_mem_sections which calls
   into

  drivers/node.c: link_mem_sections() which calls

  drivers/node.c: register_mem_sect_under_node() which calls
     get_nid_for_pfn and keeps trying until the output of that matches
     the expected node (passed all the way down from
     add_memory_resource)

It is effectively the same fix as the one referred to in the fixes tag
just in the code path for a new node where the comments point out we
have to rerun the link creation because it will have failed in
register_new_memory (as there was no node at the time).  (actually that
comment is wrong now as we don't have register_new_memory any more it
got renamed to hotplug_memory_register in Pavel's patch).

Link: http://lkml.kernel.org/r/20180504085311.1240-1-Jonathan.Cameron@huawei.com
Fixes: fc44f7f9231a ("mm/memory_hotplug: don't read nid from struct page during hotplug")
Signed-off-by: Jonathan Cameron 
Reviewed-by: Pavel Tatashin 
Acked-by: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: optimize memory hotplug

2018-04-06T04:36:25+00:00

During memory hotplugging we traverse struct pages three times:

1. memset(0) in sparse_add_one_section()
2. loop in __add_section() to set do: set_page_node(page, nid); and
   SetPageReserved(page);
3. loop in memmap_init_zone() to call __init_single_pfn()

This patch removes the first two loops, and leaves only loop 3.  All
struct pages are initialized in one place, the same as it is done during
boot.

The benefits:

 - We improve memory hotplug performance because we are not evicting the
   cache several times and also reduce loop branching overhead.

 - Remove condition from hotpath in __init_single_pfn(), that was added
   in order to fix the problem that was reported by Bharata in the above
   email thread, thus also improve performance during normal boot.

 - Make memory hotplug more similar to the boot memory initialization
   path because we zero and initialize struct pages only in one
   function.

 - Simplifies memory hotplug struct page initialization code, and thus
   enables future improvements, such as multi-threading the
   initialization of struct pages in order to improve hotplug
   performance even further on larger machines.

[pasha.tatashin@oracle.com: v5]
  Link: http://lkml.kernel.org/r/20180228030308.1116-7-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180215165920.8570-7-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin 
Reviewed-by: Ingo Molnar 
Cc: Michal Hocko 
Cc: Baoquan He 
Cc: Bharata B Rao 
Cc: Daniel Jordan 
Cc: Dan Williams 
Cc: Greg Kroah-Hartman 
Cc: "H. Peter Anvin" 
Cc: Kirill A. Shutemov 
Cc: Mel Gorman 
Cc: Steven Sistare 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug: don't read nid from struct page during hotplug

2018-04-06T04:36:25+00:00

During memory hotplugging the probe routine will leave struct pages
uninitialized, the same as it is currently done during boot.  Therefore,
we do not want to access the inside of struct pages before
__init_single_page() is called during onlining.

Because during hotplug we know that pages in one memory block belong to
the same numa node, we can skip the checking.  We should keep checking
for the boot case.

[pasha.tatashin@oracle.com: s/register_new_memory()/hotplug_memory_register()]
  Link: http://lkml.kernel.org/r/20180228030308.1116-6-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180215165920.8570-6-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin 
Acked-by: Michal Hocko 
Reviewed-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Bharata B Rao 
Cc: Daniel Jordan 
Cc: Dan Williams 
Cc: Greg Kroah-Hartman 
Cc: "H. Peter Anvin" 
Cc: Kirill A. Shutemov 
Cc: Mel Gorman 
Cc: Steven Sistare 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

driver core: node: use put_device() if device_register fail

2018-03-15T13:37:04+00:00

if device_register() returned an error! Always use put_device()
to give up the reference initialized.

Signed-off-by: Arvind Yadav 
Signed-off-by: Greg Kroah-Hartman