thp, s390: thp pagetable pre-allocation for s390

This patch is part of the architecture backend for thp on s390.  It
provides the pagetable pre-allocation functions
pgtable_trans_huge_deposit() and pgtable_trans_huge_withdraw().  Unlike
other archs, s390 has no struct page * as pgtable_t, but rather a pointer
to the page table.  So instead of saving the pagetable pre- allocation
list info inside the struct page, it is being saved within the pagetable
itself.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Gerald Schaefer 2012-10-08 16:30:18 -07:00 committed by Linus Torvalds
parent 75077afbec
commit 9501d09fa3
2 changed files with 44 additions and 0 deletions

View File

@ -1166,6 +1166,12 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
#define pte_unmap(pte) do { } while (0) #define pte_unmap(pte) do { } while (0)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE #ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
#define __HAVE_ARCH_PGTABLE_WITHDRAW
extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
static inline int pmd_trans_splitting(pmd_t pmd) static inline int pmd_trans_splitting(pmd_t pmd)
{ {
return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT; return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT;

View File

@ -883,4 +883,42 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
smp_call_function(pmdp_splitting_flush_sync, NULL, 1); smp_call_function(pmdp_splitting_flush_sync, NULL, 1);
} }
} }
void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
{
struct list_head *lh = (struct list_head *) pgtable;
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
if (!mm->pmd_huge_pte)
INIT_LIST_HEAD(lh);
else
list_add(lh, (struct list_head *) mm->pmd_huge_pte);
mm->pmd_huge_pte = pgtable;
}
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
{
struct list_head *lh;
pgtable_t pgtable;
pte_t *ptep;
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
pgtable = mm->pmd_huge_pte;
lh = (struct list_head *) pgtable;
if (list_empty(lh))
mm->pmd_huge_pte = NULL;
else {
mm->pmd_huge_pte = (pgtable_t) lh->next;
list_del(lh);
}
ptep = (pte_t *) pgtable;
pte_val(*ptep) = _PAGE_TYPE_EMPTY;
ptep++;
pte_val(*ptep) = _PAGE_TYPE_EMPTY;
return pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* CONFIG_TRANSPARENT_HUGEPAGE */