kernel_optimize_test/arch/um/kernel/tlb.c
Jeff Dike 7f0536f80c uml: speed up page table walking
The previous page table walking code was horribly inefficient.  This patch
replaces it with code taken from elsewhere in the kernel.

Forking from bash is now ~5% faster and page faults are handled ~10% faster.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:13:03 -07:00

429 lines
10 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/mm.h"
#include "asm/page.h"
#include "asm/pgalloc.h"
#include "asm/pgtable.h"
#include "asm/tlbflush.h"
#include "choose-mode.h"
#include "mode_kern.h"
#include "as-layout.h"
#include "tlb.h"
#include "mem.h"
#include "mem_user.h"
#include "os.h"
static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
int r, int w, int x, struct host_vm_op *ops, int *index,
int last_filled, union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
__u64 offset;
struct host_vm_op *last;
int fd, ret = 0;
fd = phys_mapping(phys, &offset);
if(*index != -1){
last = &ops[*index];
if((last->type == MMAP) &&
(last->u.mmap.addr + last->u.mmap.len == virt) &&
(last->u.mmap.r == r) && (last->u.mmap.w == w) &&
(last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
(last->u.mmap.offset + last->u.mmap.len == offset)){
last->u.mmap.len += len;
return 0;
}
}
if(*index == last_filled){
ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
*index = -1;
}
ops[++*index] = ((struct host_vm_op) { .type = MMAP,
.u = { .mmap = {
.addr = virt,
.len = len,
.r = r,
.w = w,
.x = x,
.fd = fd,
.offset = offset }
} });
return ret;
}
static int add_munmap(unsigned long addr, unsigned long len,
struct host_vm_op *ops, int *index, int last_filled,
union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
struct host_vm_op *last;
int ret = 0;
if(*index != -1){
last = &ops[*index];
if((last->type == MUNMAP) &&
(last->u.munmap.addr + last->u.mmap.len == addr)){
last->u.munmap.len += len;
return 0;
}
}
if(*index == last_filled){
ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
*index = -1;
}
ops[++*index] = ((struct host_vm_op) { .type = MUNMAP,
.u = { .munmap = {
.addr = addr,
.len = len } } });
return ret;
}
static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
int x, struct host_vm_op *ops, int *index,
int last_filled, union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
struct host_vm_op *last;
int ret = 0;
if(*index != -1){
last = &ops[*index];
if((last->type == MPROTECT) &&
(last->u.mprotect.addr + last->u.mprotect.len == addr) &&
(last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
(last->u.mprotect.x == x)){
last->u.mprotect.len += len;
return 0;
}
}
if(*index == last_filled){
ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
*index = -1;
}
ops[++*index] = ((struct host_vm_op) { .type = MPROTECT,
.u = { .mprotect = {
.addr = addr,
.len = len,
.r = r,
.w = w,
.x = x } } });
return ret;
}
#define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end, struct host_vm_op *ops,
int last_op, int *op_index, int force,
union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *,
struct host_vm_op *, int, int,
void **))
{
pte_t *pte;
int r, w, x, ret = 0;
pte = pte_offset_kernel(pmd, addr);
do {
r = pte_read(*pte);
w = pte_write(*pte);
x = pte_exec(*pte);
if (!pte_young(*pte)) {
r = 0;
w = 0;
} else if (!pte_dirty(*pte)) {
w = 0;
}
if(force || pte_newpage(*pte)){
if(pte_present(*pte))
ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
PAGE_SIZE, r, w, x, ops,
op_index, last_op, mmu, flush,
do_ops);
else ret = add_munmap(addr, PAGE_SIZE, ops, op_index,
last_op, mmu, flush, do_ops);
}
else if(pte_newprot(*pte))
ret = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
op_index, last_op, mmu, flush,
do_ops);
*pte = pte_mkuptodate(*pte);
} while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
return ret;
}
static inline int update_pmd_range(pud_t *pud, unsigned long addr,
unsigned long end, struct host_vm_op *ops,
int last_op, int *op_index, int force,
union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *,
struct host_vm_op *, int, int,
void **))
{
pmd_t *pmd;
unsigned long next;
int ret = 0;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if(!pmd_present(*pmd)){
if(force || pmd_newpage(*pmd)){
ret = add_munmap(addr, next - addr, ops,
op_index, last_op, mmu,
flush, do_ops);
pmd_mkuptodate(*pmd);
}
}
else ret = update_pte_range(pmd, addr, next, ops, last_op,
op_index, force, mmu, flush,
do_ops);
} while (pmd++, addr = next, ((addr != end) && !ret));
return ret;
}
static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
unsigned long end, struct host_vm_op *ops,
int last_op, int *op_index, int force,
union mm_context *mmu, void **flush,
int (*do_ops)(union mm_context *,
struct host_vm_op *, int, int,
void **))
{
pud_t *pud;
unsigned long next;
int ret = 0;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if(!pud_present(*pud)){
if(force || pud_newpage(*pud)){
ret = add_munmap(addr, next - addr, ops,
op_index, last_op, mmu,
flush, do_ops);
pud_mkuptodate(*pud);
}
}
else ret = update_pmd_range(pud, addr, next, ops, last_op,
op_index, force, mmu, flush,
do_ops);
} while (pud++, addr = next, ((addr != end) && !ret));
return ret;
}
void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force,
int (*do_ops)(union mm_context *, struct host_vm_op *,
int, int, void **))
{
pgd_t *pgd;
union mm_context *mmu = &mm->context;
struct host_vm_op ops[1];
unsigned long addr = start_addr, next;
int ret = 0, last_op = ARRAY_SIZE(ops) - 1, op_index = -1;
void *flush = NULL;
unsigned long long start_time, end_time;
start_time = os_nsecs();
ops[0].type = NONE;
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, end_addr);
if(!pgd_present(*pgd)){
if (force || pgd_newpage(*pgd)){
ret = add_munmap(addr, next - addr, ops,
&op_index, last_op, mmu,
&flush, do_ops);
pgd_mkuptodate(*pgd);
}
}
else ret = update_pud_range(pgd, addr, next, ops, last_op,
&op_index, force, mmu, &flush,
do_ops);
} while (pgd++, addr = next, ((addr != end_addr) && !ret));
end_time = os_nsecs();
log_info("total flush time - %Ld nsecs\n", end_time - start_time);
if(!ret)
ret = (*do_ops)(mmu, ops, op_index, 1, &flush);
/* This is not an else because ret is modified above */
if(ret) {
printk("fix_range_common: failed, killing current process\n");
force_sig(SIGKILL, current);
}
}
int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
{
struct mm_struct *mm;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long addr, last;
int updated = 0, err;
mm = &init_mm;
for(addr = start; addr < end;){
pgd = pgd_offset(mm, addr);
if(!pgd_present(*pgd)){
last = ADD_ROUND(addr, PGDIR_SIZE);
if(last > end)
last = end;
if(pgd_newpage(*pgd)){
updated = 1;
err = os_unmap_memory((void *) addr,
last - addr);
if(err < 0)
panic("munmap failed, errno = %d\n",
-err);
}
addr = last;
continue;
}
pud = pud_offset(pgd, addr);
if(!pud_present(*pud)){
last = ADD_ROUND(addr, PUD_SIZE);
if(last > end)
last = end;
if(pud_newpage(*pud)){
updated = 1;
err = os_unmap_memory((void *) addr,
last - addr);
if(err < 0)
panic("munmap failed, errno = %d\n",
-err);
}
addr = last;
continue;
}
pmd = pmd_offset(pud, addr);
if(!pmd_present(*pmd)){
last = ADD_ROUND(addr, PMD_SIZE);
if(last > end)
last = end;
if(pmd_newpage(*pmd)){
updated = 1;
err = os_unmap_memory((void *) addr,
last - addr);
if(err < 0)
panic("munmap failed, errno = %d\n",
-err);
}
addr = last;
continue;
}
pte = pte_offset_kernel(pmd, addr);
if(!pte_present(*pte) || pte_newpage(*pte)){
updated = 1;
err = os_unmap_memory((void *) addr,
PAGE_SIZE);
if(err < 0)
panic("munmap failed, errno = %d\n",
-err);
if(pte_present(*pte))
map_memory(addr,
pte_val(*pte) & PAGE_MASK,
PAGE_SIZE, 1, 1, 1);
}
else if(pte_newprot(*pte)){
updated = 1;
os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
}
addr += PAGE_SIZE;
}
return(updated);
}
pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
{
return(pgd_offset(mm, address));
}
pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
{
return(pud_offset(pgd, address));
}
pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
{
return(pmd_offset(pud, address));
}
pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
{
return(pte_offset_kernel(pmd, address));
}
pte_t *addr_pte(struct task_struct *task, unsigned long addr)
{
pgd_t *pgd = pgd_offset(task->mm, addr);
pud_t *pud = pud_offset(pgd, addr);
pmd_t *pmd = pmd_offset(pud, addr);
return(pte_offset_map(pmd, addr));
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
{
address &= PAGE_MASK;
flush_tlb_range(vma, address, address + PAGE_SIZE);
}
void flush_tlb_all(void)
{
flush_tlb_mm(current->mm);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
CHOOSE_MODE_PROC(flush_tlb_kernel_range_tt,
flush_tlb_kernel_range_common, start, end);
}
void flush_tlb_kernel_vm(void)
{
CHOOSE_MODE(flush_tlb_kernel_vm_tt(),
flush_tlb_kernel_range_common(start_vm, end_vm));
}
void __flush_tlb_one(unsigned long addr)
{
CHOOSE_MODE_PROC(__flush_tlb_one_tt, __flush_tlb_one_skas, addr);
}
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
CHOOSE_MODE_PROC(flush_tlb_range_tt, flush_tlb_range_skas, vma, start,
end);
}
void flush_tlb_mm(struct mm_struct *mm)
{
CHOOSE_MODE_PROC(flush_tlb_mm_tt, flush_tlb_mm_skas, mm);
}
void force_flush_all(void)
{
CHOOSE_MODE(force_flush_all_tt(), force_flush_all_skas());
}