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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2016-12-13 03:44:32 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-13 05:55:08 +0300
commit953c66c2b22a304dbc3c3d7fc8e8c25cd97a03d8 (patch)
treec851d72f1be182bc4ae4857ff720e34835e68371 /mm/huge_memory.c
parent1dd38b6c27d59414e89c08dd1ae9677a8e12cbc4 (diff)
downloadlinux-953c66c2b22a304dbc3c3d7fc8e8c25cd97a03d8.tar.xz
mm: THP page cache support for ppc64
Add arch specific callback in the generic THP page cache code that will deposit and withdarw preallocated page table. Archs like ppc64 use this preallocated table to store the hash pte slot information. Testing: kernel build of the patch series on tmpfs mounted with option huge=always The related thp stat: thp_fault_alloc 72939 thp_fault_fallback 60547 thp_collapse_alloc 603 thp_collapse_alloc_failed 0 thp_file_alloc 253763 thp_file_mapped 4251 thp_split_page 51518 thp_split_page_failed 1 thp_deferred_split_page 73566 thp_split_pmd 665 thp_zero_page_alloc 3 thp_zero_page_alloc_failed 0 [akpm@linux-foundation.org: remove unneeded parentheses, per Kirill] Link: http://lkml.kernel.org/r/20161113150025.17942-2-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Balbir Singh <bsingharora@gmail.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.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b54044c21076..2b44ac11178f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1380,6 +1380,15 @@ out_unlocked:
return ret;
}
+static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
+ pte_free(mm, pgtable);
+ atomic_long_dec(&mm->nr_ptes);
+}
+
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
@@ -1421,6 +1430,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
atomic_long_dec(&tlb->mm->nr_ptes);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
} else {
+ if (arch_needs_pgtable_deposit())
+ zap_deposited_table(tlb->mm, pmd);
add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR);
}
spin_unlock(ptl);
@@ -1607,6 +1618,12 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
if (!vma_is_anonymous(vma)) {
_pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd);
+ /*
+ * We are going to unmap this huge page. So
+ * just go ahead and zap it
+ */
+ if (arch_needs_pgtable_deposit())
+ zap_deposited_table(mm, pmd);
if (vma_is_dax(vma))
return;
page = pmd_page(_pmd);