linux.git/arch/um/kernel/mem.c, branch v4.19

mm, arch: remove empty_bad_page*

2017-11-16T02:21:03+00:00

empty_bad_page() and empty_bad_pte_table() seem to be relics from old
days which is not used by any code for a long time.  I have tried to
find when exactly but this is not really all that straightforward due to
many code movements - traces disappear around 2.4 times.

Anyway no code really references neither empty_bad_page nor
empty_bad_pte_table.  We only allocate the storage which is not used by
anybody so remove them.

Link: http://lkml.kernel.org/r/20171004150045.30755-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Acked-by: Ralf Baechle 
Acked-by: Ingo Molnar 
Cc: Yoshinori Sato 
Cc: David Howells 
Cc: Rich Felker 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tree wide: get rid of __GFP_REPEAT for order-0 allocations part I

2016-06-25T00:23:52+00:00

This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Cc: "David S. Miller" 
Cc: "H. Peter Anvin" 
Cc: "James E.J. Bottomley" 
Cc: "Theodore Ts'o" 
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Catalin Marinas 
Cc: Chen Liqin 
Cc: Chris Metcalf  [for tile]
Cc: Guan Xuetao 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Jan Kara 
Cc: John Crispin 
Cc: Lennox Wu 
Cc: Ley Foon Tan 
Cc: Martin Schwidefsky 
Cc: Matt Fleming 
Cc: Ralf Baechle 
Cc: Rich Felker 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

um: Remove broken highmem support

2015-04-13T19:01:02+00:00

Highmem was always buggy and experimental on UML(i386).
In times where 64 bit computers are default we can
remove that experimental code.

Signed-off-by: Richard Weinberger

um: handle pgtable_page_ctor() fail

2013-11-15T00:32:19+00:00

Signed-off-by: Kirill A. Shutemov 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/um: prepare for removing num_physpages and simplify mem_init()

2013-07-03T23:07:37+00:00

Prepare for removing num_physpages and simplify mem_init().

Signed-off-by: Jiang Liu 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: concentrate modification of totalram_pages into the mm core

2013-07-03T23:07:33+00:00

Concentrate code to modify totalram_pages into the mm core, so the arch
memory initialized code doesn't need to take care of it.  With these
changes applied, only following functions from mm core modify global
variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
free_all_bootmem_node(), adjust_managed_page_count().

With this patch applied, it will be much more easier for us to keep
totalram_pages and zone->managed_pages in consistence.

Signed-off-by: Jiang Liu 
Acked-by: David Howells 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Minchan Kim 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: enhance free_reserved_area() to support poisoning memory with zero

2013-07-03T23:07:32+00:00

Address more review comments from last round of code review.
1) Enhance free_reserved_area() to support poisoning freed memory with
   pattern '0'. This could be used to get rid of poison_init_mem()
   on ARM64.
2) A previous patch has disabled memory poison for initmem on s390
   by mistake, so restore to the original behavior.
3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().

Signed-off-by: Jiang Liu 
Cc: Geert Uytterhoeven 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Minchan Kim 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: change signature of free_reserved_area() to fix building warnings

2013-07-03T23:07:32+00:00

Change signature of free_reserved_area() according to Russell King's
suggestion to fix following build warnings:

  arch/arm/mm/init.c: In function 'mem_init':
  arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
    free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
    ^
  In file included from include/linux/mman.h:4:0,
                   from arch/arm/mm/init.c:15:
  include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
   extern unsigned long free_reserved_area(unsigned long start, unsigned long end,

   mm/page_alloc.c: In function 'free_reserved_area':
>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
   In file included from arch/mips/include/asm/page.h:49:0,
                    from include/linux/mmzone.h:20,
                    from include/linux/gfp.h:4,
                    from include/linux/mm.h:8,
                    from mm/page_alloc.c:18:
   arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
   mm/page_alloc.c: In function 'free_area_init_nodes':
   mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]

Also address some minor code review comments.

Signed-off-by: Jiang Liu 
Reported-by: Arnd Bergmann 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Minchan Kim 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/um: use free_highmem_page() to free highmem pages into buddy system

2013-04-29T22:54:32+00:00

Use helper function free_highmem_page() to free highmem pages into
the buddy system.

Signed-off-by: Jiang Liu 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/um: use common help functions to free reserved pages

2013-04-29T22:54:31+00:00

Use common help functions to free reserved pages.

Signed-off-by: Jiang Liu 
Cc: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds