[PATCH 05/20] arm: mmu_gather rework

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

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Fix up the arm mmu_gather code to conform to the new API.

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/arm/include/asm/tlb.h |   53 +++++++++++++++++++++++++++++++--------------
 1 file changed, 37 insertions(+), 16 deletions(-)

Index: linux-2.6/arch/arm/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/arm/include/asm/tlb.h
+++ linux-2.6/arch/arm/include/asm/tlb.h
@@ -41,12 +41,12 @@
  */
 #if defined(CONFIG_SMP) || defined(CONFIG_CPU_32v7)
 #define tlb_fast_mode(tlb)	0
-#define FREE_PTE_NR		500
 #else
 #define tlb_fast_mode(tlb)	1
-#define FREE_PTE_NR		0
 #endif
 
+#define MMU_GATHER_BUNDLE	8
+
 /*
  * TLB handling.  This allows us to remove pages from the page
  * tables, and efficiently handle the TLB issues.
@@ -58,7 +58,9 @@ struct mmu_gather {
 	unsigned long		range_start;
 	unsigned long		range_end;
 	unsigned int		nr;
-	struct page		*pages[FREE_PTE_NR];
+	unsigned int		max;
+	struct page		**pages;
+	struct page		*local[MMU_GATHER_BUNDLE];
 };
 
 DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
@@ -97,26 +99,37 @@ static inline void tlb_add_flush(struct 
 	}
 }
 
+static inline void __tlb_alloc_page(struct mmu_gather *tlb)
+{
+	unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
+
+	if (addr) {
+		tlb->pages = (void *)addr;
+		tlb->max = PAGE_SIZE / sizeof(struct page *);
+	}
+}
+
 static inline void tlb_flush_mmu(struct mmu_gather *tlb)
 {
 	tlb_flush(tlb);
 	if (!tlb_fast_mode(tlb)) {
 		free_pages_and_swap_cache(tlb->pages, tlb->nr);
 		tlb->nr = 0;
+		if (tlb->pages == tlb->local)
+			__tlb_alloc_page(tlb);
 	}
 }
 
-static inline struct mmu_gather *
-tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
+static inline void
+tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int fullmm)
 {
-	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
-
 	tlb->mm = mm;
-	tlb->fullmm = full_mm_flush;
+	tlb->fullmm = fullmm;
 	tlb->vma = NULL;
+	tlb->max = ARRAY_SIZE(tlb->local);
+	tlb->pages = tlb->local;
 	tlb->nr = 0;
-
-	return tlb;
+	__tlb_alloc_page(tlb);
 }
 
 static inline void
@@ -127,7 +140,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, u
 	/* keep the page table cache within bounds */
 	check_pgt_cache();
 
-	put_cpu_var(mmu_gathers);
+	if (tlb->pages != tlb->local)
+		free_pages((unsigned long)tlb->pages, 0);
 }
 
 /*
@@ -162,15 +176,22 @@ tlb_end_vma(struct mmu_gather *tlb, stru
 		tlb_flush(tlb);
 }
 
-static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 {
 	if (tlb_fast_mode(tlb)) {
 		free_page_and_swap_cache(page);
-	} else {
-		tlb->pages[tlb->nr++] = page;
-		if (tlb->nr >= FREE_PTE_NR)
-			tlb_flush_mmu(tlb);
+		return 1; /* avoid calling tlb_flush_mmu */
 	}
+
+	tlb->pages[tlb->nr++] = page;
+	VM_BUG_ON(tlb->nr > tlb->max);
+	return tlb->max - tlb->nr;
+}
+
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+	if (!__tlb_remove_page(tlb, page))
+		tlb_flush_mmu(tlb);
 }
 
 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,


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