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| author |   David Hildenbrand <david@redhat.com> | 2021-09-09 18:22:48 +0200 |
|---|---|---|
| committer |   Christian Borntraeger <borntraeger@de.ibm.com> | 2021-10-25 09:20:38 +0200 |
| commit | 14ea40e22c4193ed71cd93ec79c0c05216c3600a (patch) | |
| tree | caf24ec7912d219703a5d1acf7afc73d637c5041 /arch/s390/mm | |
| parent | s390/mm: optimize set_guest_storage_key() (diff) | |
| download | linux-dev-14ea40e22c4193ed71cd93ec79c0c05216c3600a.tar.xz linux-dev-14ea40e22c4193ed71cd93ec79c0c05216c3600a.zip | |
s390/mm: optimize reset_guest_reference_bit()
We already optimize get_guest_storage_key() to assume that if we don't have
a PTE table and don't have a huge page mapped that the storage key is 0.
Similarly, optimize reset_guest_reference_bit() to simply do nothing if
there is no PTE table and no huge page mapped.
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210909162248.14969-10-david@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 1c9aeb361f8d..c16232cd0ec5 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -901,13 +901,23 @@ int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr) pte_t *ptep; int cc = 0; - if (pmd_lookup(mm, addr, &pmdp)) + /* + * If we don't have a PTE table and if there is no huge page mapped, + * the storage key is 0 and there is nothing for us to do. + */ + switch (pmd_lookup(mm, addr, &pmdp)) { + case -ENOENT: + return 0; + case 0: + break; + default: return -EFAULT; + } ptl = pmd_lock(mm, pmdp); if (!pmd_present(*pmdp)) { spin_unlock(ptl); - return -EFAULT; + return 0; } if (pmd_large(*pmdp)) { |