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…6-nommu

* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu:
  NOMMU: Support XIP on initramfs
  NOMMU: Teach kobjsize() about VMA regions.
  FLAT: Don't attempt to expand the userspace stack to fill the space allocated
  FDPIC: Don't attempt to expand the userspace stack to fill the space allocated
  NOMMU: Improve procfs output using per-MM VMAs
  NOMMU: Make mmap allocation page trimming behaviour configurable.
  NOMMU: Make VMAs per MM as for MMU-mode linux
  NOMMU: Delete askedalloc and realalloc variables
  NOMMU: Rename ARM's struct vm_region
  NOMMU: Fix cleanup handling in ramfs_nommu_get_umapped_area()
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torvalds committed Jan 9, 2009
2 parents 1a7d0f0 + cb6ff20 commit c40f6f8
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Showing 29 changed files with 992 additions and 521 deletions.
31 changes: 26 additions & 5 deletions Documentation/nommu-mmap.txt
Original file line number Diff line number Diff line change
Expand Up @@ -109,12 +109,18 @@ and it's also much more restricted in the latter case:
FURTHER NOTES ON NO-MMU MMAP
============================

(*) A request for a private mapping of less than a page in size may not return
a page-aligned buffer. This is because the kernel calls kmalloc() to
allocate the buffer, not get_free_page().
(*) A request for a private mapping of a file may return a buffer that is not
page-aligned. This is because XIP may take place, and the data may not be
paged aligned in the backing store.

(*) A list of all the mappings on the system is visible through /proc/maps in
no-MMU mode.
(*) A request for an anonymous mapping will always be page aligned. If
possible the size of the request should be a power of two otherwise some
of the space may be wasted as the kernel must allocate a power-of-2
granule but will only discard the excess if appropriately configured as
this has an effect on fragmentation.

(*) A list of all the private copy and anonymous mappings on the system is
visible through /proc/maps in no-MMU mode.

(*) A list of all the mappings in use by a process is visible through
/proc/<pid>/maps in no-MMU mode.
Expand Down Expand Up @@ -242,3 +248,18 @@ PROVIDING SHAREABLE BLOCK DEVICE SUPPORT
Provision of shared mappings on block device files is exactly the same as for
character devices. If there isn't a real device underneath, then the driver
should allocate sufficient contiguous memory to honour any supported mapping.


=================================
ADJUSTING PAGE TRIMMING BEHAVIOUR
=================================

NOMMU mmap automatically rounds up to the nearest power-of-2 number of pages
when performing an allocation. This can have adverse effects on memory
fragmentation, and as such, is left configurable. The default behaviour is to
aggressively trim allocations and discard any excess pages back in to the page
allocator. In order to retain finer-grained control over fragmentation, this
behaviour can either be disabled completely, or bumped up to a higher page
watermark where trimming begins.

Page trimming behaviour is configurable via the sysctl `vm.nr_trim_pages'.
18 changes: 18 additions & 0 deletions Documentation/sysctl/vm.txt
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@ Currently, these files are in /proc/sys/vm:
- numa_zonelist_order
- nr_hugepages
- nr_overcommit_hugepages
- nr_trim_pages (only if CONFIG_MMU=n)

==============================================================

Expand Down Expand Up @@ -348,3 +349,20 @@ Change the maximum size of the hugepage pool. The maximum is
nr_hugepages + nr_overcommit_hugepages.

See Documentation/vm/hugetlbpage.txt

==============================================================

nr_trim_pages

This is available only on NOMMU kernels.

This value adjusts the excess page trimming behaviour of power-of-2 aligned
NOMMU mmap allocations.

A value of 0 disables trimming of allocations entirely, while a value of 1
trims excess pages aggressively. Any value >= 1 acts as the watermark where
trimming of allocations is initiated.

The default value is 1.

See Documentation/nommu-mmap.txt for more information.
1 change: 0 additions & 1 deletion arch/arm/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,6 @@ typedef struct {
* modified for 2.6 by Hyok S. Choi <[email protected]>
*/
typedef struct {
struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;

Expand Down
28 changes: 14 additions & 14 deletions arch/arm/mm/dma-mapping.c
Original file line number Diff line number Diff line change
Expand Up @@ -71,28 +71,28 @@ static DEFINE_SPINLOCK(consistent_lock);
* the amount of RAM found at boot time.) I would imagine that get_vm_area()
* would have to initialise this each time prior to calling vm_region_alloc().
*/
struct vm_region {
struct arm_vm_region {
struct list_head vm_list;
unsigned long vm_start;
unsigned long vm_end;
struct page *vm_pages;
int vm_active;
};

static struct vm_region consistent_head = {
static struct arm_vm_region consistent_head = {
.vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
.vm_start = CONSISTENT_BASE,
.vm_end = CONSISTENT_END,
};

static struct vm_region *
vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
static struct arm_vm_region *
arm_vm_region_alloc(struct arm_vm_region *head, size_t size, gfp_t gfp)
{
unsigned long addr = head->vm_start, end = head->vm_end - size;
unsigned long flags;
struct vm_region *c, *new;
struct arm_vm_region *c, *new;

new = kmalloc(sizeof(struct vm_region), gfp);
new = kmalloc(sizeof(struct arm_vm_region), gfp);
if (!new)
goto out;

Expand Down Expand Up @@ -127,9 +127,9 @@ vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
return NULL;
}

static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
static struct arm_vm_region *arm_vm_region_find(struct arm_vm_region *head, unsigned long addr)
{
struct vm_region *c;
struct arm_vm_region *c;

list_for_each_entry(c, &head->vm_list, vm_list) {
if (c->vm_active && c->vm_start == addr)
Expand All @@ -149,7 +149,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
pgprot_t prot)
{
struct page *page;
struct vm_region *c;
struct arm_vm_region *c;
unsigned long order;
u64 mask = ISA_DMA_THRESHOLD, limit;

Expand Down Expand Up @@ -214,7 +214,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
/*
* Allocate a virtual address in the consistent mapping region.
*/
c = vm_region_alloc(&consistent_head, size,
c = arm_vm_region_alloc(&consistent_head, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
if (c) {
pte_t *pte;
Expand Down Expand Up @@ -311,13 +311,13 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
unsigned long flags, user_size, kern_size;
struct vm_region *c;
struct arm_vm_region *c;
int ret = -ENXIO;

user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;

spin_lock_irqsave(&consistent_lock, flags);
c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
spin_unlock_irqrestore(&consistent_lock, flags);

if (c) {
Expand Down Expand Up @@ -359,7 +359,7 @@ EXPORT_SYMBOL(dma_mmap_writecombine);
*/
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
struct vm_region *c;
struct arm_vm_region *c;
unsigned long flags, addr;
pte_t *ptep;
int idx;
Expand All @@ -378,7 +378,7 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
size = PAGE_ALIGN(size);

spin_lock_irqsave(&consistent_lock, flags);
c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
if (!c)
goto no_area;

Expand Down
1 change: 0 additions & 1 deletion arch/blackfin/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,6 @@ struct sram_list_struct {
};

typedef struct {
struct vm_list_struct *vmlist;
unsigned long end_brk;
unsigned long stack_start;

Expand Down
6 changes: 3 additions & 3 deletions arch/blackfin/kernel/ptrace.c
Original file line number Diff line number Diff line change
Expand Up @@ -160,15 +160,15 @@ put_reg(struct task_struct *task, int regno, unsigned long data)
static inline int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len)
{
struct vm_list_struct *vml;
struct vm_area_struct *vma;
struct sram_list_struct *sraml;

/* overflow */
if (start + len < start)
return -EIO;

for (vml = child->mm->context.vmlist; vml; vml = vml->next)
if (start >= vml->vma->vm_start && start + len < vml->vma->vm_end)
vma = find_vma(child->mm, start);
if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
return 0;

for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
Expand Down
11 changes: 6 additions & 5 deletions arch/blackfin/kernel/traps.c
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/rbtree.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/cplb.h>
Expand Down Expand Up @@ -83,6 +84,7 @@ static void decode_address(char *buf, unsigned long address)
struct mm_struct *mm;
unsigned long flags, offset;
unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();
struct rb_node *n;

#ifdef CONFIG_KALLSYMS
unsigned long symsize;
Expand Down Expand Up @@ -128,9 +130,10 @@ static void decode_address(char *buf, unsigned long address)
if (!mm)
continue;

vml = mm->context.vmlist;
while (vml) {
struct vm_area_struct *vma = vml->vma;
for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
struct vm_area_struct *vma;

vma = rb_entry(n, struct vm_area_struct, vm_rb);

if (address >= vma->vm_start && address < vma->vm_end) {
char _tmpbuf[256];
Expand Down Expand Up @@ -176,8 +179,6 @@ static void decode_address(char *buf, unsigned long address)

goto done;
}

vml = vml->next;
}
if (!in_atomic)
mmput(mm);
Expand Down
11 changes: 6 additions & 5 deletions arch/frv/kernel/ptrace.c
Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,8 @@ static inline int put_reg(struct task_struct *task, int regno,
}

/*
* check that an address falls within the bounds of the target process's memory mappings
* check that an address falls within the bounds of the target process's memory
* mappings
*/
static inline int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len)
Expand All @@ -79,11 +80,11 @@ static inline int is_user_addr_valid(struct task_struct *child,
return -EIO;
return 0;
#else
struct vm_list_struct *vml;
struct vm_area_struct *vma;

for (vml = child->mm->context.vmlist; vml; vml = vml->next)
if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
return 0;
vma = find_vma(child->mm, start);
if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
return 0;

return -EIO;
#endif
Expand Down
1 change: 0 additions & 1 deletion arch/h8300/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,6 @@
/* Copyright (C) 2002, David McCullough <[email protected]> */

typedef struct {
struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;

Expand Down
1 change: 0 additions & 1 deletion arch/m68knommu/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,6 @@
/* Copyright (C) 2002, David McCullough <[email protected]> */

typedef struct {
struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;

Expand Down
1 change: 0 additions & 1 deletion arch/sh/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,6 @@ typedef struct {
mm_context_id_t id;
void *vdso;
#else
struct vm_list_struct *vmlist;
unsigned long end_brk;
#endif
#ifdef CONFIG_BINFMT_ELF_FDPIC
Expand Down
35 changes: 3 additions & 32 deletions fs/binfmt_elf_fdpic.c
Original file line number Diff line number Diff line change
Expand Up @@ -168,9 +168,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
struct elf_fdpic_params exec_params, interp_params;
struct elf_phdr *phdr;
unsigned long stack_size, entryaddr;
#ifndef CONFIG_MMU
unsigned long fullsize;
#endif
#ifdef ELF_FDPIC_PLAT_INIT
unsigned long dynaddr;
#endif
Expand Down Expand Up @@ -390,11 +387,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
goto error_kill;
}

/* expand the stack mapping to use up the entire allocation granule */
fullsize = kobjsize((char *) current->mm->start_brk);
if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
fullsize, 0, 0)))
stack_size = fullsize;
up_write(&current->mm->mmap_sem);

current->mm->brk = current->mm->start_brk;
Expand Down Expand Up @@ -1567,11 +1559,9 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size,
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
unsigned long *limit, unsigned long mm_flags)
{
struct vm_list_struct *vml;

for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
struct vm_area_struct *vma = vml->vma;
struct vm_area_struct *vma;

for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
if (!maydump(vma, mm_flags))
continue;

Expand Down Expand Up @@ -1617,9 +1607,6 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
elf_fpxregset_t *xfpu = NULL;
#endif
int thread_status_size = 0;
#ifndef CONFIG_MMU
struct vm_list_struct *vml;
#endif
elf_addr_t *auxv;
unsigned long mm_flags;

Expand Down Expand Up @@ -1685,13 +1672,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
fill_prstatus(prstatus, current, signr);
elf_core_copy_regs(&prstatus->pr_reg, regs);

#ifdef CONFIG_MMU
segs = current->mm->map_count;
#else
segs = 0;
for (vml = current->mm->context.vmlist; vml; vml = vml->next)
segs++;
#endif
#ifdef ELF_CORE_EXTRA_PHDRS
segs += ELF_CORE_EXTRA_PHDRS;
#endif
Expand Down Expand Up @@ -1766,20 +1747,10 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
mm_flags = current->mm->flags;

/* write program headers for segments dump */
for (
#ifdef CONFIG_MMU
vma = current->mm->mmap; vma; vma = vma->vm_next
#else
vml = current->mm->context.vmlist; vml; vml = vml->next
#endif
) {
for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
struct elf_phdr phdr;
size_t sz;

#ifndef CONFIG_MMU
vma = vml->vma;
#endif

sz = vma->vm_end - vma->vm_start;

phdr.p_type = PT_LOAD;
Expand Down
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