linux-toradex.git/mm/page_ext.c, branch v5.17

mm: make some vars and functions static or __init

2022-01-15T14:30:31+00:00

"page_idle_ops" as a global var, but its scope of use within this
document.  So it should be static.

"page_ext_ops" is a var used in the kernel initial phase.  And other
functions are aslo used in the kernel initial phase.  So they should be
__init or __initdata to reclaim memory.

Link: https://lkml.kernel.org/r/20211217095023.67293-1-liuting.0x7c00@bytedance.com
Signed-off-by: Ting Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: page table check

2022-01-15T14:30:28+00:00

Check user page table entries at the time they are added and removed.

Allows to synchronously catch memory corruption issues related to double
mapping.

When a pte for an anonymous page is added into page table, we verify
that this pte does not already point to a file backed page, and vice
versa if this is a file backed page that is being added we verify that
this page does not have an anonymous mapping

We also enforce that read-only sharing for anonymous pages is allowed
(i.e.  cow after fork).  All other sharing must be for file pages.

Page table check allows to protect and debug cases where "struct page"
metadata became corrupted for some reason.  For example, when refcnt or
mapcount become invalid.

Link: https://lkml.kernel.org/r/20211221154650.1047963-4-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin 
Cc: Aneesh Kumar K.V 
Cc: Dave Hansen 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: "H. Peter Anvin" 
Cc: Hugh Dickins 
Cc: Ingo Molnar 
Cc: Jiri Slaby 
Cc: Jonathan Corbet 
Cc: Kees Cook 
Cc: Masahiro Yamada 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Sami Tolvanen 
Cc: Thomas Gleixner 
Cc: Wei Xu 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_ext.c: fix a comment

2021-11-06T20:30:34+00:00

I have noticed that the previous macro is #ifndef CONFIG_SPARSEMEM.  I
think the comment of #else should be CONFIG_SPARSEMEM.

Link: https://lkml.kernel.org/r/20211008140312.6492-1-zhangyinan2019@email.szu.edu.cn
Signed-off-by: Yinan Zhang 
Acked-by: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/migrate: add CPU hotplug to demotion #ifdef

2021-10-19T06:22:02+00:00

Once upon a time, the node demotion updates were driven solely by memory
hotplug events.  But now, there are handlers for both CPU and memory
hotplug.

However, the #ifdef around the code checks only memory hotplug.  A
system that has HOTPLUG_CPU=y but MEMORY_HOTPLUG=n would miss CPU
hotplug events.

Update the #ifdef around the common code.  Add memory and CPU-specific
#ifdefs for their handlers.  These memory/CPU #ifdefs avoid unused
function warnings when their Kconfig option is off.

[arnd@arndb.de: rework hotplug_memory_notifier() stub]
  Link: https://lkml.kernel.org/r/20211013144029.2154629-1-arnd@kernel.org

Link: https://lkml.kernel.org/r/20210924161255.E5FE8F7E@davehans-spike.ostc.intel.com
Fixes: 884a6e5d1f93 ("mm/migrate: update node demotion order on hotplug events")
Signed-off-by: Dave Hansen 
Signed-off-by: Arnd Bergmann 
Cc: "Huang, Ying" 
Cc: Michal Hocko 
Cc: Wei Xu 
Cc: Oscar Salvador 
Cc: David Rientjes 
Cc: Dan Williams 
Cc: David Hildenbrand 
Cc: Greg Thelen 
Cc: Yang Shi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/idle_page_tracking: make PG_idle reusable

2021-09-08T18:50:24+00:00

PG_idle and PG_young allow the two PTE Accessed bit users, Idle Page
Tracking and the reclaim logic concurrently work while not interfering
with each other.  That is, when they need to clear the Accessed bit, they
set PG_young to represent the previous state of the bit, respectively.
And when they need to read the bit, if the bit is cleared, they further
read the PG_young to know whether the other has cleared the bit meanwhile
or not.

For yet another user of the PTE Accessed bit, we could add another page
flag, or extend the mechanism to use the flags.  For the DAMON usecase,
however, we don't need to do that just yet.  IDLE_PAGE_TRACKING and DAMON
are mutually exclusive, so there's only ever going to be one user of the
current set of flags.

In this commit, we split out the CONFIG options to allow for the use of
PG_young and PG_idle outside of idle page tracking.

In the next commit, DAMON's reference implementation of the virtual memory
address space monitoring primitives will use it.

[sjpark@amazon.de: set PAGE_EXTENSION for non-64BIT]
  Link: https://lkml.kernel.org/r/20210806095153.6444-1-sj38.park@gmail.com
[akpm@linux-foundation.org: tweak Kconfig text]
[sjpark@amazon.de: hide PAGE_IDLE_FLAG from users]
  Link: https://lkml.kernel.org/r/20210813081238.34705-1-sj38.park@gmail.com

Link: https://lkml.kernel.org/r/20210716081449.22187-5-sj38.park@gmail.com
Signed-off-by: SeongJae Park 
Reviewed-by: Shakeel Butt 
Reviewed-by: Fernand Sieber 
Cc: Alexander Shishkin 
Cc: Amit Shah 
Cc: Benjamin Herrenschmidt 
Cc: Brendan Higgins 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: David Woodhouse 
Cc: Fan Du 
Cc: Greg Kroah-Hartman 
Cc: Greg Thelen 
Cc: Ingo Molnar 
Cc: Joe Perches 
Cc: Jonathan Cameron 
Cc: Jonathan Corbet 
Cc: Leonard Foerster 
Cc: Marco Elver 
Cc: Markus Boehme 
Cc: Maximilian Heyne 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Shuah Khan 
Cc: Steven Rostedt (VMware) 
Cc: Vladimir Davydov 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM

2021-06-29T17:53:55+00:00

After removal of the DISCONTIGMEM memory model the FLAT_NODE_MEM_MAP
configuration option is equivalent to FLATMEM.

Drop CONFIG_FLAT_NODE_MEM_MAP and use CONFIG_FLATMEM instead.

Link: https://lkml.kernel.org/r/20210608091316.3622-10-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Acked-by: Arnd Bergmann 
Acked-by: David Hildenbrand 
Cc: Geert Uytterhoeven 
Cc: Ivan Kokshaysky 
Cc: Jonathan Corbet 
Cc: Matt Turner 
Cc: Richard Henderson 
Cc: Vineet Gupta 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix some spelling mistakes in comments

2020-12-16T06:46:19+00:00

Fix some spelling mistakes in comments:
	udpate ==> update
	succesful ==> successful
	exmaple ==> example
	unneccessary ==> unnecessary
	stoping ==> stopping
	uknown ==> unknown

Link: https://lkml.kernel.org/r/20201127011747.86005-1-shihaitao1@huawei.com
Signed-off-by: Haitao Shi 
Reviewed-by: Mike Rapoport 
Reviewed-by: Souptick Joarder 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix page_owner initializing issue for arm32

2020-12-15T20:13:38+00:00

Page owner of pages used by page owner itself used is missing on arm32
targets.  The reason is dummy_handle and failure_handle is not initialized
correctly.  Buddy allocator is used to initialize these two handles.
However, buddy allocator is not ready when page owner calls it.  This
change fixed that by initializing page owner after buddy initialization.

The working flow before and after this change are:
original logic:
 1. allocated memory for page_ext(using memblock).
 2. invoke the init callback of page_ext_ops like page_owner(using buddy
    allocator).
 3. initialize buddy.

after this change:
 1. allocated memory for page_ext(using memblock).
 2. initialize buddy.
 3. invoke the init callback of page_ext_ops like page_owner(using buddy
    allocator).

with the change, failure/dummy_handle can get its correct value and page
owner output for example has the one for page owner itself:

  Page allocated via order 2, mask 0x6202c0(GFP_USER|__GFP_NOWARN), pid 1006, ts 67278156558 ns
  PFN 543776 type Unmovable Block 531 type Unmovable Flags 0x0()
    init_page_owner+0x28/0x2f8
    invoke_init_callbacks_flatmem+0x24/0x34
    start_kernel+0x33c/0x5d8

Link: https://lkml.kernel.org/r/1603104925-5888-1-git-send-email-zhenhuah@codeaurora.org
Signed-off-by: Zhenhua Huang 
Acked-by: Vlastimil Babka 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_ext.c: drop pfn_present() check when onlining

2020-04-07T17:43:40+00:00

Since commit c5e79ef561b0 ("mm/memory_hotplug.c: don't allow to
online/offline memory blocks with holes") we disallow to offline any
memory with holes.  As all boot memory is online and hotplugged memory
cannot contain holes, we never online memory with holes.

This present check can be dropped.

Signed-off-by: David Hildenbrand 
Signed-off-by: Andrew Morton 
Cc: Michal Hocko 
Cc: Anshuman Khandual 
Cc: Dan Williams 
Cc: Greg Kroah-Hartman 
Cc: Pavel Tatashin 
Cc: "Rafael J. Wysocki" 
Link: http://lkml.kernel.org/r/20200127110424.5757-4-david@redhat.com
Signed-off-by: Linus Torvalds

mm/sparse: rename pfn_present() to pfn_in_present_section()

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

After introducing mem sub section concept, pfn_present() loses its literal
meaning, and will not be necessary a truth on partial populated mem
section.

Since all of the callers use it to judge an absent section, it is better
to rename pfn_present() as pfn_in_present_section().

Signed-off-by: Pingfan Liu 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Acked-by: Michael Ellerman 		[powerpc]
Cc: Dan Williams 
Cc: Michal Hocko 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Leonardo Bras 
Cc: Nathan Fontenot 
Cc: Nathan Lynch 
Link: http://lkml.kernel.org/r/1581919110-29575-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Linus Torvalds