diff options
| author | Gerald Schaefer <[email protected]> | 2012-10-08 16:30:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2012-10-09 16:22:30 +0900 |
| commit | 274023da1e8a49efa6fd9bf857f8557e5db44cdf (patch) | |
| tree | 0e741e23da15593646404f06f202c22e497b1ec4 | |
| parent | 9501d09fa3c4ca18971083dfb0c9aa1afc85f19c (diff) | |
thp, s390: disable thp for kvm host on s390
This patch is part of the architecture backend for thp on s390. It
disables thp for kvm hosts, because there is no kvm host hugepage support
so far. Existing thp mappings are split by follow_page() with FOLL_SPLIT,
and future thp mappings are prevented by setting VM_NOHUGEPAGE in
mm->def_flags.
Signed-off-by: Gerald Schaefer <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | arch/s390/mm/pgtable.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 1ca371a06516..e86a523875eb 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -787,6 +787,30 @@ void tlb_remove_table(struct mmu_gather *tlb, void *table) tlb_table_flush(tlb); } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void thp_split_vma(struct vm_area_struct *vma) +{ + unsigned long addr; + struct page *page; + + for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) { + page = follow_page(vma, addr, FOLL_SPLIT); + } +} + +void thp_split_mm(struct mm_struct *mm) +{ + struct vm_area_struct *vma = mm->mmap; + + while (vma != NULL) { + thp_split_vma(vma); + vma->vm_flags &= ~VM_HUGEPAGE; + vma->vm_flags |= VM_NOHUGEPAGE; + vma = vma->vm_next; + } +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + /* * switch on pgstes for its userspace process (for kvm) */ @@ -824,6 +848,12 @@ int s390_enable_sie(void) if (!mm) return -ENOMEM; +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* split thp mappings and disable thp for future mappings */ + thp_split_mm(mm); + mm->def_flags |= VM_NOHUGEPAGE; +#endif + /* Now lets check again if something happened */ task_lock(tsk); if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 || |