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| author | Zi Yan <zi.yan@cs.rutgers.edu> | 2017-09-09 02:10:57 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-09 04:26:45 +0300 |
| commit | 616b8371539a6c487404c3b8fb04078016dab4ba (patch) | |
| tree | 73e4967eee56e07ba8bb7f22e4eac37811a09343 /mm/pgtable-generic.c | |
| parent | 9c670ea37947a82cb6d4df69139f7e46ed71a0ac (diff) | |
| download | linux-616b8371539a6c487404c3b8fb04078016dab4ba.tar.xz | |
mm: thp: enable thp migration in generic path
Add thp migration's core code, including conversions between a PMD entry
and a swap entry, setting PMD migration entry, removing PMD migration
entry, and waiting on PMD migration entries.
This patch makes it possible to support thp migration. If you fail to
allocate a destination page as a thp, you just split the source thp as
we do now, and then enter the normal page migration. If you succeed to
allocate destination thp, you enter thp migration. Subsequent patches
actually enable thp migration for each caller of page migration by
allowing its get_new_page() callback to allocate thps.
[zi.yan@cs.rutgers.edu: fix gcc-4.9.0 -Wmissing-braces warning]
Link: http://lkml.kernel.org/r/A0ABA698-7486-46C3-B209-E95A9048B22C@cs.rutgers.edu
[akpm@linux-foundation.org: fix x86_64 allnoconfig warning]
Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/pgtable-generic.c')
| -rw-r--r-- | mm/pgtable-generic.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index c99d9512a45b..1175f6a24fdb 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -124,7 +124,8 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, { pmd_t pmd; VM_BUG_ON(address & ~HPAGE_PMD_MASK); - VM_BUG_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); + VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) && + !pmd_devmap(*pmdp)) || !pmd_present(*pmdp)); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return pmd; |