mm/mmu_gather: track page size with mmu gather and force flush if page size change

This allows an arch which needs to do special handing with respect to
different page size when flushing tlb to implement the same in mmu
gather.

Link: http://lkml.kernel.org/r/1465049193-22197-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 files changed, 93 insertions, 9 deletions

diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index a9d2aee3826f..1e25cd80589e 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -225,12 +225,24 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	}
 }
 
+static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
+					  struct page *page, int page_size)
+{
+	return __tlb_remove_page(tlb, page);
+}
+
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb,
 					 struct page *page)
 {
 	return __tlb_remove_page(tlb, page);
 }
 
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	return tlb_remove_page(tlb, page);
+}
+
 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
 	unsigned long addr)
 {
diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h
index e7da41aa9110..77e541cf0e5d 100644
--- a/arch/ia64/include/asm/tlb.h
+++ b/arch/ia64/include/asm/tlb.h
@@ -242,12 +242,24 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	}
 }
 
+static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
+					  struct page *page, int page_size)
+{
+	return __tlb_remove_page(tlb, page);
+}
+
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb,
 					 struct page *page)
 {
 	return __tlb_remove_page(tlb, page);
 }
 
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	return tlb_remove_page(tlb, page);
+}
+
 /*
  * Remove TLB entry for PTE mapped at virtual address ADDRESS.  This is called for any
  * PTE, not just those pointing to (normal) physical memory.
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index 30759b560849..15711de10403 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -98,11 +98,24 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	free_page_and_swap_cache(page);
 }
 
+static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
+					  struct page *page, int page_size)
+{
+	return __tlb_remove_page(tlb, page);
+}
+
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb,
 					 struct page *page)
 {
 	return __tlb_remove_page(tlb, page);
 }
+
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	return tlb_remove_page(tlb, page);
+}
+
 /*
  * pte_free_tlb frees a pte table and clears the CRSTE for the
  * page table from the tlb.
diff --git a/arch/sh/include/asm/tlb.h b/arch/sh/include/asm/tlb.h
index 21ae8f5546b2..025cdb1032f6 100644
--- a/arch/sh/include/asm/tlb.h
+++ b/arch/sh/include/asm/tlb.h
@@ -109,12 +109,24 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	__tlb_remove_page(tlb, page);
 }
 
+static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
+					  struct page *page, int page_size)
+{
+	return __tlb_remove_page(tlb, page);
+}
+
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb,
 					 struct page *page)
 {
 	return __tlb_remove_page(tlb, page);
 }
 
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	return tlb_remove_page(tlb, page);
+}
+
 #define pte_free_tlb(tlb, ptep, addr)	pte_free((tlb)->mm, ptep)
 #define pmd_free_tlb(tlb, pmdp, addr)	pmd_free((tlb)->mm, pmdp)
 #define pud_free_tlb(tlb, pudp, addr)	pud_free((tlb)->mm, pudp)
diff --git a/arch/um/include/asm/tlb.h b/arch/um/include/asm/tlb.h
index 3dc4cbb3c2c0..821ff0acfe17 100644
--- a/arch/um/include/asm/tlb.h
+++ b/arch/um/include/asm/tlb.h
@@ -110,12 +110,24 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	__tlb_remove_page(tlb, page);
 }
 
+static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
+					  struct page *page, int page_size)
+{
+	return __tlb_remove_page(tlb, page);
+}
+
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb,
 					 struct page *page)
 {
 	return __tlb_remove_page(tlb, page);
 }
 
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	return tlb_remove_page(tlb, page);
+}
+
 /**
  * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
  *
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 7b899a46a4cb..c6d667187608 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -112,6 +112,7 @@ struct mmu_gather {
 	 * that that we can adjust the range after the flush
 	 */
 	unsigned long addr;
+	int page_size;
 };
 
 #define HAVE_GENERIC_MMU_GATHER
@@ -120,7 +121,8 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long
 void tlb_flush_mmu(struct mmu_gather *tlb);
 void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start,
 							unsigned long end);
-bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page);
+extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
+				   int page_size);
 
 static inline void __tlb_adjust_range(struct mmu_gather *tlb,
 				      unsigned long address)
@@ -145,23 +147,36 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb)
 	}
 }
 
+static inline void tlb_remove_page_size(struct mmu_gather *tlb,
+					struct page *page, int page_size)
+{
+	if (__tlb_remove_page_size(tlb, page, page_size)) {
+		tlb_flush_mmu(tlb);
+		tlb->page_size = page_size;
+		__tlb_adjust_range(tlb, tlb->addr);
+		__tlb_remove_page_size(tlb, page, page_size);
+	}
+}
+
+static bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+	return __tlb_remove_page_size(tlb, page, PAGE_SIZE);
+}
+
 /* tlb_remove_page
  *	Similar to __tlb_remove_page but will call tlb_flush_mmu() itself when
  *	required.
  */
 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 {
-	if (__tlb_remove_page(tlb, page)) {
-		tlb_flush_mmu(tlb);
-		__tlb_adjust_range(tlb, tlb->addr);
-		__tlb_remove_page(tlb, page);
-	}
+	return tlb_remove_page_size(tlb, page, PAGE_SIZE);
 }
 
 static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb, struct page *page)
 {
 	/* active->nr should be zero when we call this */
 	VM_BUG_ON_PAGE(tlb->active->nr, page);
+	tlb->page_size = PAGE_SIZE;
 	__tlb_adjust_range(tlb, tlb->addr);
 	return __tlb_remove_page(tlb, page);
 }
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 343a2b7e57aa..23d1bf42fef1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1689,7 +1689,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
 		atomic_long_dec(&tlb->mm->nr_ptes);
 		spin_unlock(ptl);
-		tlb_remove_page(tlb, page);
+		tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE);
 	}
 	return 1;
 }
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 524c078ce67b..a9a8c313d133 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3250,7 +3250,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		page_remove_rmap(page, true);
 
 		spin_unlock(ptl);
-		tlb_remove_page(tlb, page);
+		tlb_remove_page_size(tlb, page, huge_page_size(h));
 		/*
 		 * Bail out after unmapping reference page if supplied
 		 */
diff --git a/mm/memory.c b/mm/memory.c
index 12f31501c323..a329149e1c54 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -233,6 +233,7 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long
 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
 	tlb->batch = NULL;
 #endif
+	tlb->page_size = 0;
 
 	__tlb_reset_range(tlb);
 }
@@ -294,12 +295,19 @@ void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long e
  *	When out of page slots we must call tlb_flush_mmu().
  *returns true if the caller should flush.
  */
-bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_size)
 {
 	struct mmu_gather_batch *batch;
 
 	VM_BUG_ON(!tlb->end);
 
+	if (!tlb->page_size)
+		tlb->page_size = page_size;
+	else {
+		if (page_size != tlb->page_size)
+			return true;
+	}
+
 	batch = tlb->active;
 	if (batch->nr == batch->max) {
 		if (!tlb_next_batch(tlb))