linux-stable.git/include/linux/mm_types.h, branch v4.18.2

mm: add hmm_data to struct page

2018-06-08T00:34:37+00:00

Make hmm_data an explicit member of the struct page union.

Link: http://lkml.kernel.org/r/20180518194519.3820-14-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: add pt_mm to struct page

2018-06-08T00:34:37+00:00

For pgd page table pages, x86 overloads the page->index field to store a
pointer to the mm_struct.  Rename this to pt_mm so it's visible to other
users.

Link: http://lkml.kernel.org/r/20180518194519.3820-13-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: improve struct page documentation

2018-06-08T00:34:37+00:00

Rewrite the documentation to describe what you can use in struct page
rather than what you can't.

Link: http://lkml.kernel.org/r/20180518194519.3820-12-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Reviewed-by: Randy Dunlap 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: combine LRU and main union in struct page

2018-06-08T00:34:37+00:00

This gives us five words of space in a single union in struct page.  The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.

Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move lru union within struct page

2018-06-08T00:34:37+00:00

Since the LRU is two words, this does not affect the double-word alignment
of SLUB's freelist.

Link: http://lkml.kernel.org/r/20180518194519.3820-10-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: combine first three unions in struct page

2018-06-08T00:34:37+00:00

By combining these three one-word unions into one three-word union, we
make it easier for users to add their own multi-word fields to struct
page, as well as making it obvious that SLUB needs to keep its double-word
alignment for its freelist & counters.

No field moves position; verified with pahole.

Link: http://lkml.kernel.org/r/20180518194519.3820-8-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Kirill A. Shutemov 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move _refcount out of struct page union

2018-06-08T00:34:37+00:00

Keeping the refcount in the union only encourages people to put something
else in the union which will overlap with _refcount and eventually explode
messily.  pahole reports no fields change location.

Link: http://lkml.kernel.org/r/20180518194519.3820-7-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move 'private' union within struct page

2018-06-08T00:34:37+00:00

By moving page->private to the fourth word of struct page, we can put the
SLUB counters in the same word as SLAB's s_mem and still do the
cmpxchg_double trick.  Now the SLUB counters no longer overlap with the
mapcount or refcount so we can drop the call to page_mapcount_reset() and
simplify set_page_slub_counters() to a single line.

Link: http://lkml.kernel.org/r/20180518194519.3820-6-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: switch s_mem and slab_cache in struct page

2018-06-08T00:34:37+00:00

This will allow us to store slub's counters in the same bits as slab's
s_mem.  slub now needs to set page->mapping to NULL as it frees the page,
just like slab does.

Link: http://lkml.kernel.org/r/20180518194519.3820-5-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Christoph Lameter 
Acked-by: Vlastimil Babka 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: split page_type out from _mapcount

2018-06-08T00:34:37+00:00

We're already using a union of many fields here, so stop abusing the
_mapcount and make page_type its own field.  That implies renaming some of
the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring
back the PG_buddy, PG_balloon and PG_kmemcg names.

As suggested by Kirill, make page_type a bitmask.  Because it starts out
life as -1 (thanks to sharing the storage with _mapcount), setting a page
flag means clearing the appropriate bit.  This gives us space for probably
twenty or so extra bits (depending how paranoid we want to be about
_mapcount underflow).

Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Kirill A. Shutemov 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds