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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-01-15 16:53:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-15 17:56:32 -0800
commitba98828088ad3ffa7ee4d5b017c291934fcbaeb9 (patch)
treeb6bc26a757c9c7855d258b8aca414937c88865ec /mm/huge_memory.c
parenteef1b3ba053aa68967d294c80a50c4a26db30f52 (diff)
downloadop-kernel-dev-ba98828088ad3ffa7ee4d5b017c291934fcbaeb9.zip
op-kernel-dev-ba98828088ad3ffa7ee4d5b017c291934fcbaeb9.tar.gz
thp: add option to setup migration entries during PMD split
We are going to use migration PTE entries to stabilize page counts. If the page is mapped with PMDs we need to split the PMD and setup migration entries. It's reasonable to combine these operations to avoid double-scanning over the page table. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 22ab365..9135593 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2695,7 +2695,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
}
static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long haddr)
+ unsigned long haddr, bool freeze)
{
struct mm_struct *mm = vma->vm_mm;
struct page *page;
@@ -2739,12 +2739,18 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
* transferred to avoid any possibility of altering
* permissions across VMAs.
*/
- entry = mk_pte(page + i, vma->vm_page_prot);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- if (!write)
- entry = pte_wrprotect(entry);
- if (!young)
- entry = pte_mkold(entry);
+ if (freeze) {
+ swp_entry_t swp_entry;
+ swp_entry = make_migration_entry(page + i, write);
+ entry = swp_entry_to_pte(swp_entry);
+ } else {
+ entry = mk_pte(page + i, vma->vm_page_prot);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (!write)
+ entry = pte_wrprotect(entry);
+ if (!young)
+ entry = pte_mkold(entry);
+ }
pte = pte_offset_map(&_pmd, haddr);
BUG_ON(!pte_none(*pte));
set_pte_at(mm, haddr, pte, entry);
@@ -2785,7 +2791,7 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PMD_SIZE);
ptl = pmd_lock(mm, pmd);
if (likely(pmd_trans_huge(*pmd)))
- __split_huge_pmd_locked(vma, pmd, haddr);
+ __split_huge_pmd_locked(vma, pmd, haddr, false);
spin_unlock(ptl);
mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PMD_SIZE);
}
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