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| author | Nitin Gupta <nitin.m.gupta@oracle.com> | 2016-03-30 11:17:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-05-20 18:44:27 -0700 |
| commit | 24e49ee3d76b70853a96520e46b8837e5eae65b2 (patch) | |
| tree | 4893dd3011dc7a4db11082ce6953d1e1d2c13803 /arch/sparc/mm/hugetlbpage.c | |
| parent | b1ac6b7b4061f6c92bacf6938f94fb61b2fbf7f3 (diff) | |
| download | blackbird-op-linux-24e49ee3d76b70853a96520e46b8837e5eae65b2.tar.gz blackbird-op-linux-24e49ee3d76b70853a96520e46b8837e5eae65b2.zip | |
sparc64: Reduce TLB flushes during hugepte changes
During hugepage map/unmap, TSB and TLB flushes are currently
issued at every PAGE_SIZE'd boundary which is unnecessary.
We now issue the flush at REAL_HPAGE_SIZE boundaries only.
Without this patch workloads which unmap a large hugepage
backed VMA region get CPU lockups due to excessive TLB
flush calls.
Orabug: 22365539, 22643230, 22995196
Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/mm/hugetlbpage.c')
| -rw-r--r-- | arch/sparc/mm/hugetlbpage.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c index 4977800e9770..ba52e6466a82 100644 --- a/arch/sparc/mm/hugetlbpage.c +++ b/arch/sparc/mm/hugetlbpage.c @@ -176,17 +176,31 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t entry) { int i; + pte_t orig[2]; + unsigned long nptes; if (!pte_present(*ptep) && pte_present(entry)) mm->context.huge_pte_count++; addr &= HPAGE_MASK; - for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { - set_pte_at(mm, addr, ptep, entry); + + nptes = 1 << HUGETLB_PAGE_ORDER; + orig[0] = *ptep; + orig[1] = *(ptep + nptes / 2); + for (i = 0; i < nptes; i++) { + *ptep = entry; ptep++; addr += PAGE_SIZE; pte_val(entry) += PAGE_SIZE; } + + /* Issue TLB flush at REAL_HPAGE_SIZE boundaries */ + addr -= REAL_HPAGE_SIZE; + ptep -= nptes / 2; + maybe_tlb_batch_add(mm, addr, ptep, orig[1], 0); + addr -= REAL_HPAGE_SIZE; + ptep -= nptes / 2; + maybe_tlb_batch_add(mm, addr, ptep, orig[0], 0); } pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, @@ -194,19 +208,28 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, { pte_t entry; int i; + unsigned long nptes; entry = *ptep; if (pte_present(entry)) mm->context.huge_pte_count--; addr &= HPAGE_MASK; - - for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { - pte_clear(mm, addr, ptep); + nptes = 1 << HUGETLB_PAGE_ORDER; + for (i = 0; i < nptes; i++) { + *ptep = __pte(0UL); addr += PAGE_SIZE; ptep++; } + /* Issue TLB flush at REAL_HPAGE_SIZE boundaries */ + addr -= REAL_HPAGE_SIZE; + ptep -= nptes / 2; + maybe_tlb_batch_add(mm, addr, ptep, entry, 0); + addr -= REAL_HPAGE_SIZE; + ptep -= nptes / 2; + maybe_tlb_batch_add(mm, addr, ptep, entry, 0); + return entry; } |
