lkml.org 
[lkml]   [2011]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH 00/20] mm: Preemptibility -v10
From
Date
On Fri, 2011-04-01 at 14:12 +0200, Peter Zijlstra wrote:
>
> Also provided is a rollup of these patches, which is used as a commit in the
> git tree referenced below.

If only I'd actually added it ;-)

---
Subject: mm: mmu_gather rework
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri, 26 Nov 2010 15:38:51 +0100
Remove the first obstackle towards a fully preemptible mmu_gather.

The current scheme assumes mmu_gather is always done with preemption
disabled and uses per-cpu storage for the page batches. Change this to
try and allocate a page for batching and in case of failure, use a
small on-stack array to make some progress.

Preemptible mmu_gather is desired in general and usable once
i_mmap_lock becomes a mutex. Doing it before the mutex conversion
saves us from having to rework the code by moving the mmu_gather
bits inside the pte_lock.

Also avoid flushing the tlb batches from under the pte lock,
this is useful even without the i_mmap_lock conversion as it
significantly reduces pte lock hold times.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
arch/alpha/mm/init.c | 2 -
arch/arm/include/asm/tlb.h | 53 ++++++++++++-----
arch/arm/mm/mmu.c | 2 -
arch/avr32/mm/init.c | 2 -
arch/cris/mm/init.c | 2 -
arch/frv/mm/init.c | 2 -
arch/ia64/include/asm/tlb.h | 66 +++++++++++++++-------
arch/ia64/mm/init.c | 2 -
arch/m32r/mm/init.c | 2 -
arch/m68k/mm/init_mm.c | 2 -
arch/microblaze/mm/init.c | 2 -
arch/mips/mm/init.c | 2 -
arch/mn10300/mm/init.c | 2 -
arch/parisc/mm/init.c | 2 -
arch/powerpc/include/asm/pgalloc.h | 4 +-
arch/powerpc/include/asm/thread_info.h | 2 +
arch/powerpc/include/asm/tlb.h | 10 +++
arch/powerpc/kernel/process.c | 23 +++++++-
arch/powerpc/mm/pgtable.c | 14 +---
arch/powerpc/mm/tlb_hash32.c | 2 +-
arch/powerpc/mm/tlb_hash64.c | 6 +-
arch/powerpc/mm/tlb_nohash.c | 2 +-
arch/s390/include/asm/tlb.h | 62 ++++++++++++--------
arch/s390/mm/pgtable.c | 1 -
arch/score/mm/init.c | 2 -
arch/sh/include/asm/tlb.h | 28 ++++++----
arch/sh/mm/init.c | 1 -
arch/sparc/include/asm/pgalloc_64.h | 3 +
arch/sparc/include/asm/pgtable_64.h | 15 ++++-
arch/sparc/include/asm/tlb_64.h | 91 ++----------------------------
arch/sparc/include/asm/tlbflush_64.h | 12 +++-
arch/sparc/mm/init_32.c | 2 -
arch/sparc/mm/tlb.c | 43 ++++++++------
arch/sparc/mm/tsb.c | 15 +++--
arch/tile/mm/init.c | 2 -
arch/um/include/asm/tlb.h | 29 ++++------
arch/um/kernel/smp.c | 3 -
arch/unicore32/mm/mmu.c | 2 -
arch/x86/mm/init.c | 2 -
arch/xtensa/mm/mmu.c | 2 -
fs/exec.c | 10 ++--
include/asm-generic/tlb.h | 96 +++++++++++++++++++++++---------
include/linux/mm.h | 2 +-
mm/memory.c | 46 ++++++++--------
mm/mmap.c | 18 +++---
45 files changed, 364 insertions(+), 329 deletions(-)
diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index 86425ab..69d0c57 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -32,8 +32,6 @@
#include <asm/console.h>
#include <asm/tlb.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
extern void die_if_kernel(char *,struct pt_regs *,long);

static struct pcb_struct original_pcb;
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index 82dfe5d..265f908 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/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 mmu_gather *tlb, unsigned long addr)
}
}

+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, bool 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, unsigned long start, unsigned long end)
/* 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, struct vm_area_struct *vma)
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,
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 6cf76b3..08a9236 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -31,8 +31,6 @@

#include "mm.h"

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
diff --git a/arch/avr32/mm/init.c b/arch/avr32/mm/init.c
index a7314d4..2798c2d 100644
--- a/arch/avr32/mm/init.c
+++ b/arch/avr32/mm/init.c
@@ -25,8 +25,6 @@
#include <asm/setup.h>
#include <asm/sections.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;

struct page *empty_zero_page;
diff --git a/arch/cris/mm/init.c b/arch/cris/mm/init.c
index df33ab8..d72ab58 100644
--- a/arch/cris/mm/init.c
+++ b/arch/cris/mm/init.c
@@ -13,8 +13,6 @@
#include <linux/bootmem.h>
#include <asm/tlb.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
unsigned long empty_zero_page;

extern char _stext, _edata, _etext; /* From linkerscript */
diff --git a/arch/frv/mm/init.c b/arch/frv/mm/init.c
index ed64588..fbe5f0d 100644
--- a/arch/frv/mm/init.c
+++ b/arch/frv/mm/init.c
@@ -41,8 +41,6 @@

#undef DEBUG

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* BAD_PAGE is the page that is used for page faults when linux
* is out-of-memory. Older versions of linux just did a
diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h
index 23cce99..c3ffe3e 100644
--- a/arch/ia64/include/asm/tlb.h
+++ b/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[NR_CPUS];
#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 *tlb, unsigned long start, unsigned long e
}
}

-/*
- * 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, unsigned int full_mm_flush)
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, unsigned int full_mm_flush)
* 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, unsigned long start, unsigned long end)
/* 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 +210,33 @@ tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
* 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 1; /* avoid calling tlb_flush_mmu */
}
+
+ 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);
+ VM_BUG_ON(tlb->nr > tlb->max);
+
+ return tlb->max - tlb->nr;
+}
+
+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);
}

/*
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index ed41759..00cb0e2 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -36,8 +36,6 @@
#include <asm/mca.h>
#include <asm/paravirt.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
extern void ia64_tlb_init (void);

unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
diff --git a/arch/m32r/mm/init.c b/arch/m32r/mm/init.c
index 73e2205..78b660e 100644
--- a/arch/m32r/mm/init.c
+++ b/arch/m32r/mm/init.c
@@ -35,8 +35,6 @@ extern char __init_begin, __init_end;

pgd_t swapper_pg_dir[1024];

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* Cache of MMU context last used.
*/
diff --git a/arch/m68k/mm/init_mm.c b/arch/m68k/mm/init_mm.c
index 8bc8425..9113c2f 100644
--- a/arch/m68k/mm/init_mm.c
+++ b/arch/m68k/mm/init_mm.c
@@ -32,8 +32,6 @@
#include <asm/sections.h>
#include <asm/tlb.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
pg_data_t pg_data_map[MAX_NUMNODES];
EXPORT_SYMBOL(pg_data_map);

diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index c843786..213f2d6 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -32,8 +32,6 @@ unsigned int __page_offset;
EXPORT_SYMBOL(__page_offset);

#else
-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
static int init_bootmem_done;
#endif /* CONFIG_MMU */

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 279599e..1aadeb4 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -64,8 +64,6 @@

#endif /* CONFIG_MIPS_MT_SMTC */

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* We have up to 8 empty zeroed pages so we can map one of the right colour
* when needed. This is necessary only on R4000 / R4400 SC and MC versions
diff --git a/arch/mn10300/mm/init.c b/arch/mn10300/mm/init.c
index 48907cc..1380182 100644
--- a/arch/mn10300/mm/init.c
+++ b/arch/mn10300/mm/init.c
@@ -37,8 +37,6 @@
#include <asm/tlb.h>
#include <asm/sections.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
unsigned long highstart_pfn, highend_pfn;

#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index b7ed8d7..102f872 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -31,8 +31,6 @@
#include <asm/mmzone.h>
#include <asm/sections.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
extern int data_start;

#ifdef CONFIG_DISCONTIGMEM
diff --git a/arch/powerpc/include/asm/pgalloc.h b/arch/powerpc/include/asm/pgalloc.h
index abe8532..df1b4cb 100644
--- a/arch/powerpc/include/asm/pgalloc.h
+++ b/arch/powerpc/include/asm/pgalloc.h
@@ -32,13 +32,13 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)

#ifdef CONFIG_SMP
extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift);
-extern void pte_free_finish(void);
+extern void pte_free_finish(struct mmu_gather *tlb);
#else /* CONFIG_SMP */
static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift)
{
pgtable_free(table, shift);
}
-static inline void pte_free_finish(void) { }
+static inline void pte_free_finish(struct mmu_gather *tlb) { }
#endif /* !CONFIG_SMP */

static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *ptepage,
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index d8529ef..37c353e 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -139,10 +139,12 @@ static inline struct thread_info *current_thread_info(void)
#define TLF_NAPPING 0 /* idle thread enabled NAP mode */
#define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */
#define TLF_RESTORE_SIGMASK 2 /* Restore signal mask in do_signal */
+#define TLF_LAZY_MMU 3 /* tlb_batch is active */

#define _TLF_NAPPING (1 << TLF_NAPPING)
#define _TLF_SLEEPING (1 << TLF_SLEEPING)
#define _TLF_RESTORE_SIGMASK (1 << TLF_RESTORE_SIGMASK)
+#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU)

#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK 1
diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
index e2b428b..8f0ed7a 100644
--- a/arch/powerpc/include/asm/tlb.h
+++ b/arch/powerpc/include/asm/tlb.h
@@ -28,6 +28,16 @@
#define tlb_start_vma(tlb, vma) do { } while (0)
#define tlb_end_vma(tlb, vma) do { } while (0)

+#define HAVE_ARCH_MMU_GATHER 1
+
+struct pte_freelist_batch;
+
+struct arch_mmu_gather {
+ struct pte_freelist_batch *batch;
+};
+
+#define ARCH_MMU_GATHER_INIT (struct arch_mmu_gather){ .batch = NULL, }
+
extern void tlb_flush(struct mmu_gather *tlb);

/* Get the generic bits... */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f74f355..3e37f37 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -395,6 +395,9 @@ struct task_struct *__switch_to(struct task_struct *prev,
struct thread_struct *new_thread, *old_thread;
unsigned long flags;
struct task_struct *last;
+#ifdef CONFIG_PPC_BOOK3S_64
+ struct ppc64_tlb_batch *batch;
+#endif

#ifdef CONFIG_SMP
/* avoid complexity of lazy save/restore of fpu
@@ -513,7 +516,17 @@ struct task_struct *__switch_to(struct task_struct *prev,
old_thread->accum_tb += (current_tb - start_tb);
new_thread->start_tb = current_tb;
}
-#endif
+#endif /* CONFIG_PPC64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ batch = &__get_cpu_var(ppc64_tlb_batch);
+ if (batch->active) {
+ current_thread_info()->local_flags |= _TLF_LAZY_MMU;
+ if (batch->index)
+ __flush_tlb_pending(batch);
+ batch->active = 0;
+ }
+#endif /* CONFIG_PPC_BOOK3S_64 */

local_irq_save(flags);

@@ -528,6 +541,14 @@ struct task_struct *__switch_to(struct task_struct *prev,
hard_irq_disable();
last = _switch(old_thread, new_thread);

+#ifdef CONFIG_PPC_BOOK3S_64
+ if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
+ current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
+ batch = &__get_cpu_var(ppc64_tlb_batch);
+ batch->active = 1;
+ }
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
local_irq_restore(flags);

return last;
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 6a3997f..6e72788 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -33,8 +33,6 @@

#include "mmu_decl.h"

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
#ifdef CONFIG_SMP

/*
@@ -43,7 +41,6 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
* freeing a page table page that is being walked without locks
*/

-static DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
static unsigned long pte_freelist_forced_free;

struct pte_freelist_batch
@@ -97,12 +94,10 @@ static void pte_free_submit(struct pte_freelist_batch *batch)

void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift)
{
- /* This is safe since tlb_gather_mmu has disabled preemption */
- struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
+ struct pte_freelist_batch **batchp = &tlb->arch.batch;
unsigned long pgf;

- if (atomic_read(&tlb->mm->mm_users) < 2 ||
- cpumask_equal(mm_cpumask(tlb->mm), cpumask_of(smp_processor_id()))){
+ if (atomic_read(&tlb->mm->mm_users) < 2) {
pgtable_free(table, shift);
return;
}
@@ -124,10 +119,9 @@ void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift)
}
}

-void pte_free_finish(void)
+void pte_free_finish(struct mmu_gather *tlb)
{
- /* This is safe since tlb_gather_mmu has disabled preemption */
- struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
+ struct pte_freelist_batch **batchp = &tlb->arch.batch;

if (*batchp == NULL)
return;
diff --git a/arch/powerpc/mm/tlb_hash32.c b/arch/powerpc/mm/tlb_hash32.c
index 690566b..d555cdb 100644
--- a/arch/powerpc/mm/tlb_hash32.c
+++ b/arch/powerpc/mm/tlb_hash32.c
@@ -73,7 +73,7 @@ void tlb_flush(struct mmu_gather *tlb)
}

/* Push out batch of freed page tables */
- pte_free_finish();
+ pte_free_finish(tlb);
}

/*
diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
index c14d09f..5c94ca3 100644
--- a/arch/powerpc/mm/tlb_hash64.c
+++ b/arch/powerpc/mm/tlb_hash64.c
@@ -155,7 +155,7 @@ void __flush_tlb_pending(struct ppc64_tlb_batch *batch)

void tlb_flush(struct mmu_gather *tlb)
{
- struct ppc64_tlb_batch *tlbbatch = &__get_cpu_var(ppc64_tlb_batch);
+ struct ppc64_tlb_batch *tlbbatch = &get_cpu_var(ppc64_tlb_batch);

/* If there's a TLB batch pending, then we must flush it because the
* pages are going to be freed and we really don't want to have a CPU
@@ -164,8 +164,10 @@ void tlb_flush(struct mmu_gather *tlb)
if (tlbbatch->index)
__flush_tlb_pending(tlbbatch);

+ put_cpu_var(ppc64_tlb_batch);
+
/* Push out batch of freed page tables */
- pte_free_finish();
+ pte_free_finish(tlb);
}

/**
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 2a030d8..8eaf67d 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -301,7 +301,7 @@ void tlb_flush(struct mmu_gather *tlb)
flush_tlb_mm(tlb->mm);

/* Push out batch of freed page tables */
- pte_free_finish();
+ pte_free_finish(tlb);
}

/*
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index 9074a54..77eee54 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -29,65 +29,77 @@
#include <asm/smp.h>
#include <asm/tlbflush.h>

-#ifndef CONFIG_SMP
-#define TLB_NR_PTRS 1
-#else
-#define TLB_NR_PTRS 508
-#endif
-
struct mmu_gather {
struct mm_struct *mm;
unsigned int fullmm;
unsigned int nr_ptes;
unsigned int nr_pxds;
- void *array[TLB_NR_PTRS];
+ unsigned int max;
+ void **array;
+ void *local[8];
};

-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
-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->array = (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->array = tlb->local;
tlb->fullmm = full_mm_flush;
- tlb->nr_ptes = 0;
- tlb->nr_pxds = TLB_NR_PTRS;
if (tlb->fullmm)
__tlb_flush_mm(mm);
- return tlb;
+ else
+ __tlb_alloc_page(tlb);
+ tlb->nr_ptes = 0;
+ tlb->nr_pxds = tlb->max;
}

-static inline void tlb_flush_mmu(struct mmu_gather *tlb,
- unsigned long start, unsigned long end)
+static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
- if (!tlb->fullmm && (tlb->nr_ptes > 0 || tlb->nr_pxds < TLB_NR_PTRS))
+ if (!tlb->fullmm && (tlb->nr_ptes > 0 || tlb->nr_pxds < tlb->max))
__tlb_flush_mm(tlb->mm);
while (tlb->nr_ptes > 0)
page_table_free_rcu(tlb->mm, tlb->array[--tlb->nr_ptes]);
- while (tlb->nr_pxds < TLB_NR_PTRS)
+ while (tlb->nr_pxds < tlb->max)
crst_table_free_rcu(tlb->mm, tlb->array[tlb->nr_pxds++]);
}

static inline void tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end)
{
- tlb_flush_mmu(tlb, start, end);
+ tlb_flush_mmu(tlb);

rcu_table_freelist_finish();

/* keep the page table cache within bounds */
check_pgt_cache();

- put_cpu_var(mmu_gathers);
+ if (tlb->array != tlb->local)
+ free_pages((unsigned long) tlb->array, 0);
}

/*
* Release the page cache reference for a pte removed by
- * tlb_ptep_clear_flush. In both flush modes the tlb fo a page cache page
+ * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page
* has already been freed, so just do free_page_and_swap_cache.
*/
+static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ free_page_and_swap_cache(page);
+ return 1; /* avoid calling tlb_flush_mmu */
+}
+
static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
free_page_and_swap_cache(page);
@@ -103,7 +115,7 @@ static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
if (!tlb->fullmm) {
tlb->array[tlb->nr_ptes++] = pte;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
page_table_free(tlb->mm, (unsigned long *) pte);
}
@@ -124,7 +136,7 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
if (!tlb->fullmm) {
tlb->array[--tlb->nr_pxds] = pmd;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
crst_table_free(tlb->mm, (unsigned long *) pmd);
#endif
@@ -146,7 +158,7 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
if (!tlb->fullmm) {
tlb->array[--tlb->nr_pxds] = pud;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
crst_table_free(tlb->mm, (unsigned long *) pud);
#endif
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index e1850c2..07fcc3f 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -36,7 +36,6 @@ struct rcu_table_freelist {
((PAGE_SIZE - sizeof(struct rcu_table_freelist)) \
/ sizeof(unsigned long))

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
static DEFINE_PER_CPU(struct rcu_table_freelist *, rcu_table_freelist);

static void __page_table_free(struct mm_struct *mm, unsigned long *table);
diff --git a/arch/score/mm/init.c b/arch/score/mm/init.c
index 50fdec5..cee6bce 100644
--- a/arch/score/mm/init.c
+++ b/arch/score/mm/init.c
@@ -38,8 +38,6 @@
#include <asm/sections.h>
#include <asm/tlb.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
unsigned long empty_zero_page;
EXPORT_SYMBOL_GPL(empty_zero_page);

diff --git a/arch/sh/include/asm/tlb.h b/arch/sh/include/asm/tlb.h
index 75abb38..6c308d8 100644
--- a/arch/sh/include/asm/tlb.h
+++ b/arch/sh/include/asm/tlb.h
@@ -23,8 +23,6 @@ struct mmu_gather {
unsigned long start, end;
};

-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
static inline void init_tlb_gather(struct mmu_gather *tlb)
{
tlb->start = TASK_SIZE;
@@ -36,17 +34,13 @@ static inline void init_tlb_gather(struct mmu_gather *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 full_mm_flush)
{
- struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
-
tlb->mm = mm;
tlb->fullmm = full_mm_flush;

init_tlb_gather(tlb);
-
- return tlb;
}

static inline void
@@ -57,8 +51,6 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)

/* keep the page table cache within bounds */
check_pgt_cache();
-
- put_cpu_var(mmu_gathers);
}

static inline void
@@ -91,7 +83,21 @@ tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
}
}

-#define tlb_remove_page(tlb,page) free_page_and_swap_cache(page)
+static inline void tlb_flush_mmu(struct mmu_gather *tlb)
+{
+}
+
+static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ free_page_and_swap_cache(page);
+ return 1; /* avoid calling tlb_flush_mmu */
+}
+
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ __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/sh/mm/init.c b/arch/sh/mm/init.c
index 0d3f912..58a93fb3 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -28,7 +28,6 @@
#include <asm/cache.h>
#include <asm/sizes.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD];

void __init generic_mem_init(void)
diff --git a/arch/sparc/include/asm/pgalloc_64.h b/arch/sparc/include/asm/pgalloc_64.h
index 5bdfa2c..4e5e087 100644
--- a/arch/sparc/include/asm/pgalloc_64.h
+++ b/arch/sparc/include/asm/pgalloc_64.h
@@ -78,4 +78,7 @@ static inline void check_pgt_cache(void)
quicklist_trim(0, NULL, 25, 16);
}

+#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
+#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
+
#endif /* _SPARC64_PGALLOC_H */
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index f8dddb7..b2e85bf 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -655,9 +655,11 @@ static inline int pte_special(pte_t pte)
#define pte_unmap(pte) do { } while (0)

/* Actual page table PTE updates. */
-extern void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig);
+extern void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+ pte_t *ptep, pte_t orig, int fullmm);

-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, int fullmm)
{
pte_t orig = *ptep;

@@ -670,12 +672,19 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *p
* and SUN4V pte layout, so this inline test is fine.
*/
if (likely(mm != &init_mm) && (pte_val(orig) & _PAGE_VALID))
- tlb_batch_add(mm, addr, ptep, orig);
+ tlb_batch_add(mm, addr, ptep, orig, fullmm);
}

+#define set_pte_at(mm,addr,ptep,pte) \
+ __set_pte_at((mm), (addr), (ptep), (pte), 0)
+
#define pte_clear(mm,addr,ptep) \
set_pte_at((mm), (addr), (ptep), __pte(0UL))

+#define __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
+#define pte_clear_not_present_full(mm,addr,ptep,fullmm) \
+ __set_pte_at((mm), (addr), (ptep), __pte(0UL), (fullmm))
+
#ifdef DCACHE_ALIASING_POSSIBLE
#define __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) \
diff --git a/arch/sparc/include/asm/tlb_64.h b/arch/sparc/include/asm/tlb_64.h
index dca406b..190e189 100644
--- a/arch/sparc/include/asm/tlb_64.h
+++ b/arch/sparc/include/asm/tlb_64.h
@@ -7,66 +7,11 @@
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>

-#define TLB_BATCH_NR 192
-
-/*
- * For UP we don't need to worry about TLB flush
- * and page free order so much..
- */
-#ifdef CONFIG_SMP
- #define FREE_PTE_NR 506
- #define tlb_fast_mode(bp) ((bp)->pages_nr == ~0U)
-#else
- #define FREE_PTE_NR 1
- #define tlb_fast_mode(bp) 1
-#endif
-
-struct mmu_gather {
- struct mm_struct *mm;
- unsigned int pages_nr;
- unsigned int need_flush;
- unsigned int fullmm;
- unsigned int tlb_nr;
- unsigned long vaddrs[TLB_BATCH_NR];
- struct page *pages[FREE_PTE_NR];
-};
-
-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
#ifdef CONFIG_SMP
extern void smp_flush_tlb_pending(struct mm_struct *,
unsigned long, unsigned long *);
#endif

-extern void __flush_tlb_pending(unsigned long, unsigned long, unsigned long *);
-extern void flush_tlb_pending(void);
-
-static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
-{
- struct mmu_gather *mp = &get_cpu_var(mmu_gathers);
-
- BUG_ON(mp->tlb_nr);
-
- mp->mm = mm;
- mp->pages_nr = num_online_cpus() > 1 ? 0U : ~0U;
- mp->fullmm = full_mm_flush;
-
- return mp;
-}
-
-
-static inline void tlb_flush_mmu(struct mmu_gather *mp)
-{
- if (!mp->fullmm)
- flush_tlb_pending();
- if (mp->need_flush) {
- free_pages_and_swap_cache(mp->pages, mp->pages_nr);
- mp->pages_nr = 0;
- mp->need_flush = 0;
- }
-
-}
-
#ifdef CONFIG_SMP
extern void smp_flush_tlb_mm(struct mm_struct *mm);
#define do_flush_tlb_mm(mm) smp_flush_tlb_mm(mm)
@@ -74,38 +19,14 @@ extern void smp_flush_tlb_mm(struct mm_struct *mm);
#define do_flush_tlb_mm(mm) __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT)
#endif

-static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, unsigned long end)
-{
- tlb_flush_mmu(mp);
-
- if (mp->fullmm)
- mp->fullmm = 0;
-
- /* keep the page table cache within bounds */
- check_pgt_cache();
-
- put_cpu_var(mmu_gathers);
-}
-
-static inline void tlb_remove_page(struct mmu_gather *mp, struct page *page)
-{
- if (tlb_fast_mode(mp)) {
- free_page_and_swap_cache(page);
- return;
- }
- mp->need_flush = 1;
- mp->pages[mp->pages_nr++] = page;
- if (mp->pages_nr >= FREE_PTE_NR)
- tlb_flush_mmu(mp);
-}
-
-#define tlb_remove_tlb_entry(mp,ptep,addr) do { } while (0)
-#define pte_free_tlb(mp, ptepage, addr) pte_free((mp)->mm, ptepage)
-#define pmd_free_tlb(mp, pmdp, addr) pmd_free((mp)->mm, pmdp)
-#define pud_free_tlb(tlb,pudp, addr) __pud_free_tlb(tlb,pudp,addr)
+extern void __flush_tlb_pending(unsigned long, unsigned long, unsigned long *);
+extern void flush_tlb_pending(void);

-#define tlb_migrate_finish(mm) do { } while (0)
#define tlb_start_vma(tlb, vma) do { } while (0)
#define tlb_end_vma(tlb, vma) do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
+#define tlb_flush(tlb) flush_tlb_pending()
+
+#include <asm-generic/tlb.h>

#endif /* _SPARC64_TLB_H */
diff --git a/arch/sparc/include/asm/tlbflush_64.h b/arch/sparc/include/asm/tlbflush_64.h
index fbb675d..2ef4634 100644
--- a/arch/sparc/include/asm/tlbflush_64.h
+++ b/arch/sparc/include/asm/tlbflush_64.h
@@ -5,9 +5,17 @@
#include <asm/mmu_context.h>

/* TSB flush operations. */
-struct mmu_gather;
+
+#define TLB_BATCH_NR 192
+
+struct tlb_batch {
+ struct mm_struct *mm;
+ unsigned long tlb_nr;
+ unsigned long vaddrs[TLB_BATCH_NR];
+};
+
extern void flush_tsb_kernel_range(unsigned long start, unsigned long end);
-extern void flush_tsb_user(struct mmu_gather *mp);
+extern void flush_tsb_user(struct tlb_batch *tb);

/* TLB flush operations. */

diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index 4c31e2b..a755487 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -37,8 +37,6 @@
#include <asm/prom.h>
#include <asm/leon.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
unsigned long *sparc_valid_addr_bitmap;
EXPORT_SYMBOL(sparc_valid_addr_bitmap);

diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index d8f21e2..b1f279c 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -19,33 +19,34 @@

/* Heavily inspired by the ppc64 code. */

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);

void flush_tlb_pending(void)
{
- struct mmu_gather *mp = &get_cpu_var(mmu_gathers);
+ struct tlb_batch *tb = &get_cpu_var(tlb_batch);

- if (mp->tlb_nr) {
- flush_tsb_user(mp);
+ if (tb->tlb_nr) {
+ flush_tsb_user(tb);

- if (CTX_VALID(mp->mm->context)) {
+ if (CTX_VALID(tb->mm->context)) {
#ifdef CONFIG_SMP
- smp_flush_tlb_pending(mp->mm, mp->tlb_nr,
- &mp->vaddrs[0]);
+ smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
+ &tb->vaddrs[0]);
#else
- __flush_tlb_pending(CTX_HWBITS(mp->mm->context),
- mp->tlb_nr, &mp->vaddrs[0]);
+ __flush_tlb_pending(CTX_HWBITS(tb->mm->context),
+ tb->tlb_nr, &tb->vaddrs[0]);
#endif
}
- mp->tlb_nr = 0;
+ tb->tlb_nr = 0;
}

- put_cpu_var(mmu_gathers);
+ put_cpu_var(tlb_batch);
}

-void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig)
+void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+ pte_t *ptep, pte_t orig, int fullmm)
{
- struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);
+ struct tlb_batch *tb = &get_cpu_var(tlb_batch);
unsigned long nr;

vaddr &= PAGE_MASK;
@@ -77,21 +78,25 @@ void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t

no_cache_flush:

- if (mp->fullmm)
+ if (fullmm) {
+ put_cpu_var(tlb_batch);
return;
+ }

- nr = mp->tlb_nr;
+ nr = tb->tlb_nr;

- if (unlikely(nr != 0 && mm != mp->mm)) {
+ if (unlikely(nr != 0 && mm != tb->mm)) {
flush_tlb_pending();
nr = 0;
}

if (nr == 0)
- mp->mm = mm;
+ tb->mm = mm;

- mp->vaddrs[nr] = vaddr;
- mp->tlb_nr = ++nr;
+ tb->vaddrs[nr] = vaddr;
+ tb->tlb_nr = ++nr;
if (nr >= TLB_BATCH_NR)
flush_tlb_pending();
+
+ put_cpu_var(tlb_batch);
}
diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 101d7c8..9484615 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -47,12 +47,13 @@ void flush_tsb_kernel_range(unsigned long start, unsigned long end)
}
}

-static void __flush_tsb_one(struct mmu_gather *mp, unsigned long hash_shift, unsigned long tsb, unsigned long nentries)
+static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
+ unsigned long tsb, unsigned long nentries)
{
unsigned long i;

- for (i = 0; i < mp->tlb_nr; i++) {
- unsigned long v = mp->vaddrs[i];
+ for (i = 0; i < tb->tlb_nr; i++) {
+ unsigned long v = tb->vaddrs[i];
unsigned long tag, ent, hash;

v &= ~0x1UL;
@@ -65,9 +66,9 @@ static void __flush_tsb_one(struct mmu_gather *mp, unsigned long hash_shift, uns
}
}

-void flush_tsb_user(struct mmu_gather *mp)
+void flush_tsb_user(struct tlb_batch *tb)
{
- struct mm_struct *mm = mp->mm;
+ struct mm_struct *mm = tb->mm;
unsigned long nentries, base, flags;

spin_lock_irqsave(&mm->context.lock, flags);
@@ -76,7 +77,7 @@ void flush_tsb_user(struct mmu_gather *mp)
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
if (tlb_type == cheetah_plus || tlb_type == hypervisor)
base = __pa(base);
- __flush_tsb_one(mp, PAGE_SHIFT, base, nentries);
+ __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);

#ifdef CONFIG_HUGETLB_PAGE
if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
@@ -84,7 +85,7 @@ void flush_tsb_user(struct mmu_gather *mp)
nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
if (tlb_type == cheetah_plus || tlb_type == hypervisor)
base = __pa(base);
- __flush_tsb_one(mp, HPAGE_SHIFT, base, nentries);
+ __flush_tsb_one(tb, HPAGE_SHIFT, base, nentries);
}
#endif
spin_unlock_irqrestore(&mm->context.lock, flags);
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index d6e87fd..4e10c40 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -60,8 +60,6 @@ unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
EXPORT_SYMBOL(VMALLOC_RESERVE);
#endif

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/* Create an L2 page table */
static pte_t * __init alloc_pte(void)
{
diff --git a/arch/um/include/asm/tlb.h b/arch/um/include/asm/tlb.h
index 660caed..4febacd 100644
--- a/arch/um/include/asm/tlb.h
+++ b/arch/um/include/asm/tlb.h
@@ -22,9 +22,6 @@ struct mmu_gather {
unsigned int fullmm; /* non-zero means full mm flush */
};

-/* Users of the generic TLB shootdown code must declare this storage space. */
-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
unsigned long address)
{
@@ -47,27 +44,20 @@ static inline void init_tlb_gather(struct mmu_gather *tlb)
}
}

-/* tlb_gather_mmu
- * 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_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
{
- struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
-
tlb->mm = mm;
tlb->fullmm = full_mm_flush;

init_tlb_gather(tlb);
-
- return tlb;
}

extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end);

static inline void
-tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+tlb_flush_mmu(struct mmu_gather *tlb)
{
if (!tlb->need_flush)
return;
@@ -83,12 +73,10 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
- tlb_flush_mmu(tlb, start, end);
+ tlb_flush_mmu(tlb);

/* keep the page table cache within bounds */
check_pgt_cache();
-
- put_cpu_var(mmu_gathers);
}

/* tlb_remove_page
@@ -96,11 +84,16 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
* while handling the additional races in SMP caused by other CPUs
* caching valid mappings in their TLBs.
*/
-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;
free_page_and_swap_cache(page);
- return;
+ return 1; /* avoid calling tlb_flush_mmu */
+}
+
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ __tlb_remove_page(tlb, page);
}

/**
diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index 106bf27..d9011e0 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -7,9 +7,6 @@
#include "asm/pgalloc.h"
#include "asm/tlb.h"

-/* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
#ifdef CONFIG_SMP

#include "linux/sched.h"
diff --git a/arch/unicore32/mm/mmu.c b/arch/unicore32/mm/mmu.c
index 7bf3d58..c5b2b65 100644
--- a/arch/unicore32/mm/mmu.c
+++ b/arch/unicore32/mm/mmu.c
@@ -30,8 +30,6 @@

#include "mm.h"

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
/*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 286d289..cda082e 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -16,8 +16,6 @@
#include <asm/tlb.h>
#include <asm/proto.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
unsigned long __initdata pgt_buf_start;
unsigned long __meminitdata pgt_buf_end;
unsigned long __meminitdata pgt_buf_top;
diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c
index 4bb91a9..ca81654 100644
--- a/arch/xtensa/mm/mmu.c
+++ b/arch/xtensa/mm/mmu.c
@@ -14,8 +14,6 @@
#include <asm/mmu_context.h>
#include <asm/page.h>

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
void __init paging_init(void)
{
memset(swapper_pg_dir, 0, PAGE_SIZE);
diff --git a/fs/exec.c b/fs/exec.c
index 5e62d26..14e623e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -553,7 +553,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
unsigned long length = old_end - old_start;
unsigned long new_start = old_start - shift;
unsigned long new_end = old_end - shift;
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;

BUG_ON(new_start > new_end);

@@ -579,12 +579,12 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
return -ENOMEM;

lru_add_drain();
- tlb = tlb_gather_mmu(mm, 0);
+ tlb_gather_mmu(&tlb, mm, 0);
if (new_end > old_start) {
/*
* when the old and new regions overlap clear from new_end.
*/
- free_pgd_range(tlb, new_end, old_end, new_end,
+ free_pgd_range(&tlb, new_end, old_end, new_end,
vma->vm_next ? vma->vm_next->vm_start : 0);
} else {
/*
@@ -593,10 +593,10 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
* have constraints on va-space that make this illegal (IA64) -
* for the others its just a little faster.
*/
- free_pgd_range(tlb, old_start, old_end, new_end,
+ free_pgd_range(&tlb, old_start, old_end, new_end,
vma->vm_next ? vma->vm_next->vm_start : 0);
}
- tlb_finish_mmu(tlb, new_end, old_end);
+ tlb_finish_mmu(&tlb, new_end, old_end);

/*
* Shrink the vma to just the new range. Always succeeds.
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index e43f976..67f21e2 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -5,6 +5,8 @@
* Copyright 2001 Red Hat, Inc.
* Based on code from mm/memory.c Copyright Linus Torvalds and others.
*
+ * Copyright 2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
@@ -22,51 +24,71 @@
* and page free order so much..
*/
#ifdef CONFIG_SMP
- #ifdef ARCH_FREE_PTR_NR
- #define FREE_PTR_NR ARCH_FREE_PTR_NR
- #else
- #define FREE_PTE_NR 506
- #endif
#define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
#else
- #define FREE_PTE_NR 1
#define tlb_fast_mode(tlb) 1
#endif

+/*
+ * If we can't allocate a page to make a big patch of page pointers
+ * to work on, then just handle a few from the on-stack structure.
+ */
+#define MMU_GATHER_BUNDLE 8
+
/* struct mmu_gather is an opaque type used by the mm code for passing around
* any data needed by arch specific code for tlb_remove_page.
*/
struct mmu_gather {
struct mm_struct *mm;
unsigned int nr; /* set to ~0U means fast mode */
+ unsigned int max; /* nr < max */
unsigned int need_flush;/* Really unmapped some ptes? */
unsigned int fullmm; /* non-zero means full mm flush */
- struct page * pages[FREE_PTE_NR];
+#ifdef HAVE_ARCH_MMU_GATHER
+ struct arch_mmu_gather arch;
+#endif
+ struct page **pages;
+ struct page *local[MMU_GATHER_BUNDLE];
};

-/* Users of the generic TLB shootdown code must declare this storage space. */
-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
+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 *);
+ }
+}

/* tlb_gather_mmu
- * Return a pointer to an initialized struct mmu_gather.
+ * Called to initialize an (on-stack) mmu_gather structure for page-table
+ * tear-down from @mm. The @fullmm argument is used when @mm is without
+ * users and we're going to destroy the full address space (exit/execve).
*/
-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;

- /* Use fast mode if only one CPU is online */
- tlb->nr = num_online_cpus() > 1 ? 0U : ~0U;
+ tlb->max = ARRAY_SIZE(tlb->local);
+ tlb->pages = tlb->local;
+
+ if (num_online_cpus() > 1) {
+ tlb->nr = 0;
+ __tlb_alloc_page(tlb);
+ } else /* Use fast mode if only one CPU is online */
+ tlb->nr = ~0U;

- tlb->fullmm = full_mm_flush;
+ tlb->fullmm = fullmm;

- return tlb;
+#ifdef HAVE_ARCH_MMU_GATHER
+ tlb->arch = ARCH_MMU_GATHER_INIT;
+#endif
}

static inline void
-tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+tlb_flush_mmu(struct mmu_gather *tlb)
{
if (!tlb->need_flush)
return;
@@ -75,6 +97,13 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
if (!tlb_fast_mode(tlb)) {
free_pages_and_swap_cache(tlb->pages, tlb->nr);
tlb->nr = 0;
+ /*
+ * If we are using the local on-stack array of pages for MMU
+ * gather, try allocating an off-stack array again as we have
+ * recently freed pages.
+ */
+ if (tlb->pages == tlb->local)
+ __tlb_alloc_page(tlb);
}
}

@@ -85,29 +114,42 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
- tlb_flush_mmu(tlb, start, end);
+ tlb_flush_mmu(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);
}

-/* tlb_remove_page
+/* __tlb_remove_page
* Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while
* handling the additional races in SMP caused by other CPUs caching valid
- * mappings in their TLBs.
+ * mappings in their TLBs. Returns the number of free page slots left.
+ * When out of page slots we must call tlb_flush_mmu().
*/
-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 1; /* avoid calling tlb_flush_mmu() */
}
tlb->pages[tlb->nr++] = page;
- if (tlb->nr >= FREE_PTE_NR)
- tlb_flush_mmu(tlb, 0, 0);
+ VM_BUG_ON(tlb->nr > tlb->max);
+
+ return tlb->max - tlb->nr;
+}
+
+/* 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);
}

/**
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7606d7d..2bf8bf1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -904,7 +904,7 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
unsigned long size);
unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *);
-unsigned long unmap_vmas(struct mmu_gather **tlb,
+unsigned long unmap_vmas(struct mmu_gather *tlb,
struct vm_area_struct *start_vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *);
diff --git a/mm/memory.c b/mm/memory.c
index 9da8cab..e6eddc4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -912,12 +912,13 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
long *zap_work, struct zap_details *details)
{
struct mm_struct *mm = tlb->mm;
+ int force_flush = 0;
pte_t *pte;
spinlock_t *ptl;
int rss[NR_MM_COUNTERS];

init_rss_vec(rss);
-
+again:
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
arch_enter_lazy_mmu_mode();
do {
@@ -974,7 +975,9 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
page_remove_rmap(page);
if (unlikely(page_mapcount(page) < 0))
print_bad_pte(vma, addr, ptent, page);
- tlb_remove_page(tlb, page);
+ force_flush = !__tlb_remove_page(tlb, page);
+ if (force_flush)
+ break;
continue;
}
/*
@@ -1001,6 +1004,18 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
arch_leave_lazy_mmu_mode();
pte_unmap_unlock(pte - 1, ptl);

+ /*
+ * mmu_gather ran out of room to batch pages, we break out of
+ * the PTE lock to avoid doing the potential expensive TLB invalidate
+ * and page-free while holding it.
+ */
+ if (force_flush) {
+ force_flush = 0;
+ tlb_flush_mmu(tlb);
+ if (addr != end)
+ goto again;
+ }
+
return addr;
}

@@ -1121,17 +1136,14 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb,
* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
* drops the lock and schedules.
*/
-unsigned long unmap_vmas(struct mmu_gather **tlbp,
+unsigned long unmap_vmas(struct mmu_gather *tlb,
struct vm_area_struct *vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *details)
{
long zap_work = ZAP_BLOCK_SIZE;
- unsigned long tlb_start = 0; /* For tlb_finish_mmu */
- int tlb_start_valid = 0;
unsigned long start = start_addr;
spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
- int fullmm = (*tlbp)->fullmm;
struct mm_struct *mm = vma->vm_mm;

mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
@@ -1152,11 +1164,6 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
untrack_pfn_vma(vma, 0, 0);

while (start != end) {
- if (!tlb_start_valid) {
- tlb_start = start;
- tlb_start_valid = 1;
- }
-
if (unlikely(is_vm_hugetlb_page(vma))) {
/*
* It is undesirable to test vma->vm_file as it
@@ -1177,7 +1184,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,

start = end;
} else
- start = unmap_page_range(*tlbp, vma,
+ start = unmap_page_range(tlb, vma,
start, end, &zap_work, details);

if (zap_work > 0) {
@@ -1185,19 +1192,13 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
break;
}

- tlb_finish_mmu(*tlbp, tlb_start, start);
-
if (need_resched() ||
(i_mmap_lock && spin_needbreak(i_mmap_lock))) {
- if (i_mmap_lock) {
- *tlbp = NULL;
+ if (i_mmap_lock)
goto out;
- }
cond_resched();
}

- *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
- tlb_start_valid = 0;
zap_work = ZAP_BLOCK_SIZE;
}
}
@@ -1217,16 +1218,15 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details)
{
struct mm_struct *mm = vma->vm_mm;
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;
unsigned long end = address + size;
unsigned long nr_accounted = 0;

lru_add_drain();
- tlb = tlb_gather_mmu(mm, 0);
+ tlb_gather_mmu(&tlb, mm, 0);
update_hiwater_rss(mm);
end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
- if (tlb)
- tlb_finish_mmu(tlb, address, end);
+ tlb_finish_mmu(&tlb, address, end);
return end;
}

diff --git a/mm/mmap.c b/mm/mmap.c
index 2ec8eb5..f8cbc86 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1913,17 +1913,17 @@ static void unmap_region(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;
unsigned long nr_accounted = 0;

lru_add_drain();
- tlb = tlb_gather_mmu(mm, 0);
+ tlb_gather_mmu(&tlb, mm, 0);
update_hiwater_rss(mm);
unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- free_pgtables(tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
- next? next->vm_start: 0);
- tlb_finish_mmu(tlb, start, end);
+ free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
+ next ? next->vm_start : 0);
+ tlb_finish_mmu(&tlb, start, end);
}

/*
@@ -2265,7 +2265,7 @@ EXPORT_SYMBOL(do_brk);
/* Release all mmaps. */
void exit_mmap(struct mm_struct *mm)
{
- struct mmu_gather *tlb;
+ struct mmu_gather tlb;
struct vm_area_struct *vma;
unsigned long nr_accounted = 0;
unsigned long end;
@@ -2290,14 +2290,14 @@ void exit_mmap(struct mm_struct *mm)

lru_add_drain();
flush_cache_mm(mm);
- tlb = tlb_gather_mmu(mm, 1);
+ tlb_gather_mmu(&tlb, mm, 1);
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use -1 here to ensure all VMAs in the mm are unmapped */
end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);

- free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0);
- tlb_finish_mmu(tlb, 0, end);
+ free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
+ tlb_finish_mmu(&tlb, 0, end);

/*
* Walk the list again, actually closing and freeing it,


\
 
 \ /
  Last update: 2011-04-01 15:55    [from the cache]
©2003-2011 Jasper Spaans