3 files changed, 44 insertions, 10 deletions

diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index e15f33715103..b01ec72522cb 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -487,6 +487,7 @@ good_area:
 		tsb_grow(mm, MM_TSB_BASE, mm_rss);
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 	mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
+	mm_rss *= REAL_HPAGE_PER_HPAGE;
 	if (unlikely(mm_rss >
 		     mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
 		if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index 3659d37b4d81..c56a195c9071 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -174,10 +174,25 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 		return;
 
 	if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) {
-		if (pmd_val(pmd) & _PAGE_PMD_HUGE)
-			mm->context.thp_pte_count++;
-		else
-			mm->context.thp_pte_count--;
+		/*
+		 * Note that this routine only sets pmds for THP pages.
+		 * Hugetlb pages are handled elsewhere.  We need to check
+		 * for huge zero page.  Huge zero pages are like hugetlb
+		 * pages in that there is no RSS, but there is the need
+		 * for TSB entries.  So, huge zero page counts go into
+		 * hugetlb_pte_count.
+		 */
+		if (pmd_val(pmd) & _PAGE_PMD_HUGE) {
+			if (is_huge_zero_page(pmd_page(pmd)))
+				mm->context.hugetlb_pte_count++;
+			else
+				mm->context.thp_pte_count++;
+		} else {
+			if (is_huge_zero_page(pmd_page(orig)))
+				mm->context.hugetlb_pte_count--;
+			else
+				mm->context.thp_pte_count--;
+		}
 
 		/* Do not try to allocate the TSB hash table if we
 		 * don't have one already.  We have various locks held
@@ -204,6 +219,9 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	}
 }
 
+/*
+ * This routine is only called when splitting a THP
+ */
 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 		     pmd_t *pmdp)
 {
@@ -213,6 +231,15 @@ void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 
 	set_pmd_at(vma->vm_mm, address, pmdp, entry);
 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+
+	/*
+	 * set_pmd_at() will not be called in a way to decrement
+	 * thp_pte_count when splitting a THP, so do it now.
+	 * Sanity check pmd before doing the actual decrement.
+	 */
+	if ((pmd_val(entry) & _PAGE_PMD_HUGE) &&
+	    !is_huge_zero_page(pmd_page(entry)))
+		(vma->vm_mm)->context.thp_pte_count--;
 }
 
 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 266411291634..84cd593117a6 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -489,8 +489,10 @@ retry_tsb_alloc:
 
 int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
+	unsigned long mm_rss = get_mm_rss(mm);
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	unsigned long total_huge_pte_count;
+	unsigned long saved_hugetlb_pte_count;
+	unsigned long saved_thp_pte_count;
 #endif
 	unsigned int i;
 
@@ -503,10 +505,12 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 	 * will re-increment the counters as the parent PTEs are
 	 * copied into the child address space.
 	 */
-	total_huge_pte_count = mm->context.hugetlb_pte_count +
-			 mm->context.thp_pte_count;
+	saved_hugetlb_pte_count = mm->context.hugetlb_pte_count;
+	saved_thp_pte_count = mm->context.thp_pte_count;
 	mm->context.hugetlb_pte_count = 0;
 	mm->context.thp_pte_count = 0;
+
+	mm_rss -= saved_thp_pte_count * (HPAGE_SIZE / PAGE_SIZE);
 #endif
 
 	/* copy_mm() copies over the parent's mm_struct before calling
@@ -519,11 +523,13 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 	/* If this is fork, inherit the parent's TSB size.  We would
 	 * grow it to that size on the first page fault anyways.
 	 */
-	tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
+	tsb_grow(mm, MM_TSB_BASE, mm_rss);
 
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	if (unlikely(total_huge_pte_count))
-		tsb_grow(mm, MM_TSB_HUGE, total_huge_pte_count);
+	if (unlikely(saved_hugetlb_pte_count + saved_thp_pte_count))
+		tsb_grow(mm, MM_TSB_HUGE,
+			 (saved_hugetlb_pte_count + saved_thp_pte_count) *
+			 REAL_HPAGE_PER_HPAGE);
 #endif
 
 	if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))