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| author | Steve Capper <steve.capper@linaro.org> | 2014-10-09 15:29:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 22:26:01 -0400 |
| commit | b8cd51afe05a98ef907e61c603d5c5b7ad6242d8 (patch) | |
| tree | b0da97d39da9ddd9dabf5f033e9c0555ec374e6e /arch/arm/mm | |
| parent | a0ad5496b2b3accf09ab9485ad0170e3b4b1cb27 (diff) | |
| download | blackbird-op-linux-b8cd51afe05a98ef907e61c603d5c5b7ad6242d8.tar.gz blackbird-op-linux-b8cd51afe05a98ef907e61c603d5c5b7ad6242d8.zip | |
arm: mm: enable RCU fast_gup
Activate the RCU fast_gup for ARM. We also need to force THP splits to
broadcast an IPI s.t. we block in the fast_gup page walker. As THP
splits are comparatively rare, this should not lead to a noticeable
performance degradation.
Some pre-requisite functions pud_write and pud_page are also added.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dann Frazier <dann.frazier@canonical.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/flush.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 43d54f5b26b9..265b836b3bd1 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -400,3 +400,18 @@ void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned l */ __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE); } + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_t pmd = pmd_mksplitting(*pmdp); + VM_BUG_ON(address & ~PMD_MASK); + set_pmd_at(vma->vm_mm, address, pmdp, pmd); + + /* dummy IPI to serialise against fast_gup */ + kick_all_cpus_sync(); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
