From 24e49ee3d76b70853a96520e46b8837e5eae65b2 Mon Sep 17 00:00:00 2001 From: Nitin Gupta Date: Wed, 30 Mar 2016 11:17:13 -0700 Subject: 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 Signed-off-by: David S. Miller --- arch/sparc/mm/hugetlbpage.c | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) (limited to 'arch/sparc/mm/hugetlbpage.c') 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; } -- cgit