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| author | David Miller <davem@davemloft.net> | 2012-10-09 03:34:29 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 11:23:06 +0400 |
| commit | 9e695d2ecc8451cc2c1603d60b5c8e7f5581923a (patch) | |
| tree | 77528ae73fe70d1bae3ced18a50e59fd81d2372c /arch/sparc/include/asm/page_64.h | |
| parent | f5c8ad47284ca01dafc37da5a72bb9644174d387 (diff) | |
| download | linux-9e695d2ecc8451cc2c1603d60b5c8e7f5581923a.tar.xz | |
sparc64: Support transparent huge pages.
This is relatively easy since PMD's now cover exactly 4MB of memory.
Our PMD entries are 32-bits each, so we use a special encoding. The
lowest bit, PMD_ISHUGE, determines the interpretation. This is possible
because sparc64's page tables are purely software entities so we can use
whatever encoding scheme we want. We just have to make the TLB miss
assembler page table walkers aware of the layout.
set_pmd_at() works much like set_pte_at() but it has to operate in two
page from a table of non-huge PTEs, so we have to queue up TLB flushes
based upon what mappings are valid in the PTE table. In the second regime
we are going from huge-page to non-huge-page, and in that case we need
only queue up a single TLB flush to push out the huge page mapping.
We still have 5 bits remaining in the huge PMD encoding so we can very
likely support any new pieces of THP state tracking that might get added
in the future.
With lots of help from Johannes Weiner.
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/sparc/include/asm/page_64.h')
| -rw-r--r-- | arch/sparc/include/asm/page_64.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/sparc/include/asm/page_64.h b/arch/sparc/include/asm/page_64.h index 087a5c505c69..4b39f74d6ca0 100644 --- a/arch/sparc/include/asm/page_64.h +++ b/arch/sparc/include/asm/page_64.h @@ -17,7 +17,7 @@ #define HPAGE_SHIFT 22 -#ifdef CONFIG_HUGETLB_PAGE +#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) #define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT) #define HPAGE_MASK (~(HPAGE_SIZE - 1UL)) #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) @@ -26,6 +26,11 @@ #ifndef __ASSEMBLY__ +#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) +struct mm_struct; +extern void hugetlb_setup(struct mm_struct *mm); +#endif + #define WANT_PAGE_VIRTUAL extern void _clear_page(void *page); |