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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2018-10-15 10:30:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-29 13:37:57 +0100
commit28a3b553dd31ae447979eec0da7b9e9c83e5d6ee (patch)
tree33c52199cd919a9f115b41a95b4c98d135e8e815
parent384221cbb918136863016a582dd7475febc7d4b9 (diff)
mm: add mm_pxd_folded checks to pgtable_bytes accounting functions
[ Upstream commit 6d212db11947ae5464e4717536ed9faf61c01e86 ] The common mm code calls mm_dec_nr_pmds() and mm_dec_nr_puds() in free_pgtables() if the address range spans a full pud or pmd. If mm_dec_nr_puds/mm_dec_nr_pmds are non-empty due to configuration settings they blindly subtract the size of the pmd or pud table from pgtable_bytes even if the pud or pmd page table layer is folded. Add explicit mm_[pmd|pud]_folded checks to the four pgtable_bytes accounting functions mm_inc_nr_puds, mm_inc_nr_pmds, mm_dec_nr_puds and mm_dec_nr_pmds. As the check for folded page tables can be overwritten by the architecture, this allows to keep a correct pgtable_bytes value for platforms that use a dynamic number of page table levels. Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--include/linux/mm.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0416a7204be3..e899460f1bc5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1724,11 +1724,15 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
static inline void mm_inc_nr_puds(struct mm_struct *mm)
{
+ if (mm_pud_folded(mm))
+ return;
atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
}
static inline void mm_dec_nr_puds(struct mm_struct *mm)
{
+ if (mm_pud_folded(mm))
+ return;
atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
}
#endif
@@ -1748,11 +1752,15 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
static inline void mm_inc_nr_pmds(struct mm_struct *mm)
{
+ if (mm_pmd_folded(mm))
+ return;
atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
}
static inline void mm_dec_nr_pmds(struct mm_struct *mm)
{
+ if (mm_pmd_folded(mm))
+ return;
atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
}
#endif