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| author |   Matthew Wilcox <mawilcox@microsoft.com> | 2018-06-07 17:08:18 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-07 17:34:37 -0700 |
| commit | 6e292b9be7f4358985ce33ae1f59ab30a8c09e08 (patch) | |
| tree | 857ddd791e19272b368e673bb192577a6c5d3e9c /kernel | |
| parent | s390: use _refcount for pgtables (diff) | |
| download | linux-dev-6e292b9be7f4358985ce33ae1f59ab30a8c09e08.tar.xz linux-dev-6e292b9be7f4358985ce33ae1f59ab30a8c09e08.zip | |
mm: split page_type out from _mapcount
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 <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/crash_core.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c index f7674d676889..b66aced5e8c2 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -460,6 +460,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_NUMBER(PG_hwpoison); #endif VMCOREINFO_NUMBER(PG_head_mask); +#define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); #ifdef CONFIG_HUGETLB_PAGE VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); |