[PATCH 07/13] ia64: mmu_gather rework

Peter Zijlstra
2011-03-02T17:54:48Z

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Fix up the ia64 mmu_gather code to conform to the new API.

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
arch/ia64/include/asm/tlb.h | 67 ++++++++++++++++++++++++++++++--------------
1 file changed, 47 insertions(+), 20 deletions(-)

Index: linux-2.6/arch/ia64/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/ia64/include/asm/tlb.h
+++ linux-2.6/arch/ia64/include/asm/tlb.h
@@ -47,21 +47,27 @@
#include <asm/machvec.h>

#ifdef CONFIG_SMP
-# define FREE_PTE_NR 2048
# define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
#else
-# define FREE_PTE_NR 0
# define tlb_fast_mode(tlb) (1)
#endif

+/*
+ * If we can't allocate a page to make a big batch of page pointers
+ * to work on, then just handle a few from the on-stack structure.
+ */
+#define IA64_GATHER_BUNDLE 8
+
struct mmu_gather {
struct mm_struct *mm;
unsigned int nr; /* == ~0U => fast mode */
+ unsigned int max;
unsigned char fullmm; /* non-zero means full mm flush */
unsigned char need_flush; /* really unmapped some PTEs? */
unsigned long start_addr;
unsigned long end_addr;
- struct page *pages[FREE_PTE_NR];
+ struct page **pages;
+ struct page *local[IA64_GATHER_BUNDLE];
};

struct ia64_tr_entry {
@@ -90,9 +96,6 @@ extern struct ia64_tr_entry *ia64_idtrs[
#define RR_RID_MASK 0x00000000ffffff00L
#define RR_TO_RID(val) ((val >> 8) & 0xffffff)

-/* Users of the generic TLB shootdown code must declare this storage space. */
-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* Flush the TLB for address range START to END and, if not in fast mode, release the
* freed pages that where gathered up to this point.
@@ -147,15 +150,23 @@ ia64_tlb_flush_mmu (struct mmu_gather *t
}
}

-/*
- * Return a pointer to an initialized struct mmu_gather.
- */
-static inline struct mmu_gather *
-tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush)
+static inline void __tlb_alloc_page(struct mmu_gather *tlb)
{
- struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
+ unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);

+ if (addr) {
+ tlb->pages = (void *)addr;
+ tlb->max = PAGE_SIZE / sizeof(void *);
+ }
+}
+
+
+static inline void
+tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
+{
tlb->mm = mm;
+ tlb->max = ARRAY_SIZE(tlb->local);
+ tlb->pages = tlb->local;
/*
* Use fast mode if only 1 CPU is online.
*
@@ -172,7 +183,6 @@ tlb_gather_mmu (struct mm_struct *mm, un
tlb->nr = (num_online_cpus() == 1) ? ~0U : 0;
tlb->fullmm = full_mm_flush;
tlb->start_addr = ~0UL;
- return tlb;
}

/*
@@ -180,7 +190,7 @@ tlb_gather_mmu (struct mm_struct *mm, un
* collected.
*/
static inline void
-tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
+tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
/*
* Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and
@@ -191,7 +201,8 @@ tlb_finish_mmu (struct mmu_gather *tlb,
/* 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);
}

/*
@@ -199,18 +210,34 @@ tlb_finish_mmu (struct mmu_gather *tlb,
* must be delayed until after the TLB has been flushed (see comments at the beginning of
* this file).
*/
-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)
{
tlb->need_flush = 1;

if (tlb_fast_mode(tlb)) {
free_page_and_swap_cache(page);
- return;
+ return 0;
}
+
+ if (!tlb->nr && tlb->pages == tlb->local)
+ __tlb_alloc_page(tlb);
+
tlb->pages[tlb->nr++] = page;
- if (tlb->nr >= FREE_PTE_NR)
- ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr);
+ if (tlb->nr >= tlb->max)
+ return 1;
+
+ return 0;
+}
+
+static inline void tlb_flush_mmu(struct mmu_gather *tlb)
+{
+ ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr);
+}
+
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ if (__tlb_remove_page(tlb, page))
+ tlb_flush_mmu(tlb);
}

/*