Skip to content

X
xv6-public
提交 372d4c19 创建 作者: Frans Kaashoek's avatar Frans Kaashoek
浏览文件
操作

Start on on-demand paging

上级 5c24b9a8
隐藏空白字符变更
内嵌 并排
正在显示 包含 87 行增加 和 25 行删除
defs.h
浏览文件 @ 372d4c19
......@@ -167,7 +167,8 @@ void kvmalloc(void);
void vmenable(void);
pde_t* setupkvm(void);
char* uva2ka(pde_t*, char*);
struct vmnode * vmn_allocpg(uint);
struct vmnode* vmn_alloc(uint, uint);
struct vmnode* vmn_allocpg(uint);
void vmn_free(struct vmnode *);
int vmn_load(struct vmnode *, struct inode*, uint, uint);
struct vmap * vmap_alloc(void);
......
exec.c
浏览文件 @ 372d4c19
......@@ -21,6 +21,9 @@ exec(char *path, char **argv)
pde_t *pgdir = 0, *oldpgdir;
struct vmap *vmap = 0, *oldvmap;
struct vmnode *vmn = 0;
int odp = 0;
cprintf("exec: %s\n", path);
if((ip = namei(path)) == 0)
return -1;
......@@ -58,16 +61,25 @@ exec(char *path, char **argv)
brk = va_end;
int npg = (va_end - va_start) / PGSIZE;
if ((vmn = vmn_allocpg(npg)) == 0)
goto bad;
if (odp) {
if ((vmn = vmn_alloc(npg, ONDEMAND)) == 0)
goto bad;
} else {
if ((vmn = vmn_allocpg(npg)) == 0)
goto bad;
}
if(vmn_load(vmn, ip, ph.offset, ph.filesz) < 0)
goto bad;
if(vmap_insert(vmap, vmn, ph.va) < 0)
goto bad;
vmn = 0;
}
iunlockput(ip);
ip = 0;
if (odp)
iunlock(ip);
else {
iunlockput(ip);
ip = 0;
}
// Allocate a vmnode for the heap.
// XXX pre-allocate 32 pages..
......
proc.h
浏览文件 @ 372d4c19
......@@ -31,6 +31,7 @@ struct context {
enum procstate { UNUSED, EMBRYO, SLEEPING, RUNNABLE, RUNNING, ZOMBIE };
enum vmatype { PRIVATE, COW};
enum vmntype { EAGER, ONDEMAND};
// Virtual memory
struct vmnode {
......@@ -38,6 +39,10 @@ struct vmnode {
char *page[32];
uint ref;
uint alloc; // in use?
enum vmntype type;
struct inode *ip;
uint offset;
uint sz;
};
struct vma {
......
vm.c
浏览文件 @ 372d4c19
......@@ -238,35 +238,43 @@ struct {
} vmaps;
struct vmnode *
vmn_alloc(void)
vmn_alloc(uint npg, uint type)
{
for(uint i = 0; i < sizeof(vmnodes.n) / sizeof(vmnodes.n[0]); i++) {
struct vmnode *n = &vmnodes.n[i];
if(n->alloc == 0 && __sync_bool_compare_and_swap(&n->alloc, 0, 1)) {
n->npages = 0;
if(npg > sizeof(n->page) / sizeof(n->page[0])) {
panic("vmnode too big\n");
}
n->npages = npg;
n->ref = 0;
n->ip = 0;
n->type = type;
return n;
}
}
panic("out of vmnodes");
}
struct vmnode *
vmn_allocpg(uint npg)
static int
vmn_doallocpg(struct vmnode *n)
{
struct vmnode *n = vmn_alloc();
if(npg > sizeof(n->page) / sizeof(n->page[0])) {
cprintf("vmnode too big: %d\n", npg);
return 0;
}
for(uint i = 0; i < npg; i++) {
for(uint i = 0; i < n->npages; i++) {
if((n->page[i] = kalloc()) == 0) {
vmn_free(n);
return 0;
return -1;
}
memset((char *) n->page[i], 0, PGSIZE);
n->npages++;
}
return 0;
}
struct vmnode *
vmn_allocpg(uint npg)
{
struct vmnode *n = vmn_alloc(npg, EAGER);
if (n == 0) return 0;
if (vmn_doallocpg(n) < 0) return 0;
return n;
}
......@@ -274,9 +282,13 @@ void
vmn_free(struct vmnode *n)
{
for(uint i = 0; i < n->npages; i++) {
kfree((char *) n->page[i]);
n->page[i] = 0;
if (n->page[i]) {
kfree((char *) n->page[i]);
n->page[i] = 0;
}
}
if (n->ip)
panic("vmn_free: drop inode ref");
n->alloc = 0;
}
......@@ -307,7 +319,7 @@ vmap_alloc(void)
if(m->alloc == 0 && __sync_bool_compare_and_swap(&m->alloc, 0, 1)) {
for(uint j = 0; j < sizeof(m->e) / sizeof(m->e[0]); j++){
m->e[j].n = 0;
m->e[i].va_type = PRIVATE;
m->e[j].va_type = PRIVATE;
m->e[j].lock.name = "vma";
}
m->lock.name = "vmap";
......@@ -415,9 +427,8 @@ vmap_copy(struct vmap *m, pde_t* pgdir, int share)
return c;
}
// Load a program segment into a vmnode.
int
vmn_load(struct vmnode *vmn, struct inode *ip, uint offset, uint sz)
static int
vmn_doload(struct vmnode *vmn, struct inode *ip, uint offset, uint sz)
{
for(uint i = 0; i < sz; i += PGSIZE){
uint n;
......@@ -432,6 +443,20 @@ vmn_load(struct vmnode *vmn, struct inode *ip, uint offset, uint sz)
return 0;
}
// Load a program segment into a vmnode.
int
vmn_load(struct vmnode *vmn, struct inode *ip, uint offset, uint sz)
{
if (vmn->type == ONDEMAND) {
vmn->ip = ip;
vmn->offset = offset;
vmn->sz = sz;
return 0;
} else {
return vmn_doload(vmn, ip, offset, sz);
}
}
// Free a page table and all the physical memory pages
// in the user part.
void
......@@ -529,12 +554,29 @@ pagefault(pde_t *pgdir, struct vmap *vmap, uint va, uint err)
if(m == 0)
return -1;
// cprintf("%d: pf addr=0x%x err 0x%x check = %d\n", proc->pid, va, err, check);
// cprintf("%d: pf vma type = %d refcnt %d pte=0x%x\n", proc->pid, m->va_type, m->n->ref, *pte);
// cprintf("%d: pf addr=0x%x err 0x%x\n", proc->pid, va, err);
// cprintf("%d: pf vma type = %d refcnt %d vmn type %d pte=0x%x\n", proc->pid, m->va_type, m->n->ref, m->n->type, *pte);
uint npg = (PGROUNDDOWN(va) - m->va_start) / PGSIZE;
if (m->n && m->n->ip && *pte == 0x0) {
//cprintf("ODP\n");
if (vmn_doallocpg(m->n) < 0) {
panic("pagefault: couldn't allocate pages");
}
release(&m->lock);
if (vmn_doload(m->n, m->n->ip, m->n->offset, m->n->sz) < 0) {
panic("pagefault: couldn't load");
}
acquire(&m->lock);
pte = walkpgdir(pgdir, (const void *)va, 0);
if (pte == 0x0)
panic("pagefault: not paged in???");
cprintf("ODP done\n");
}
if (m->va_type == COW && (err & FEC_WR)) {
// Write to a COW page
// cprintf("write to cow\n");
if (m->n->ref == 1) { // if vma isn't shared any more, make it private
m->va_type = PRIVATE;
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
......@@ -552,8 +594,10 @@ pagefault(pde_t *pgdir, struct vmap *vmap, uint va, uint err)
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
}
} else if (m->va_type == COW) {
// cprintf("cow\n");
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_COW;
} else {
// cprintf("fill in pte\n");
if (m->n->ref > 1)
panic("pagefault");
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
......
您添加了 0 人 到此讨论。请谨慎行事。
请先完成此评论的编辑！
请 注册 或者 后发表评论