s390/mm: pmdp_get_and_clear_full optimization

Analog to ptep_get_and_clear_full define a variant of the
pmpd_get_and_clear primitive which gets the full hint from the
mmu_gather struct. This allows s390 to avoid a costly instruction
when destroying an address space.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2014-10-24 10:52:29 +02:00
parent 6972cae523
commit fcbe08d66f
3 changed files with 26 additions and 1 deletions

View File

@ -1651,6 +1651,19 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
return pmd;
}
#define __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL
static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm,
unsigned long address,
pmd_t *pmdp, int full)
{
pmd_t pmd = *pmdp;
if (!full)
pmdp_flush_lazy(mm, address, pmdp);
pmd_clear(pmdp);
return pmd;
}
#define __HAVE_ARCH_PMDP_CLEAR_FLUSH
static inline pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)

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@ -103,6 +103,17 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp,
int full)
{
return pmdp_get_and_clear(mm, address, pmdp);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
unsigned long address, pte_t *ptep,

View File

@ -1400,7 +1400,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
* pgtable_trans_huge_withdraw after finishing pmdp related
* operations.
*/
orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
orig_pmd = pmdp_get_and_clear_full(tlb->mm, addr, pmd,
tlb->fullmm);
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
if (is_huge_zero_pmd(orig_pmd)) {