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xv6-public
提交 0afd1961 创建 作者: Robert Morris's avatar Robert Morris
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Merge branch 'scale' of git+ssh://pdos.csail.mit.edu/home/am0/6.828/xv6 into scale

上级 53ed1966 3ef81f58
隐藏空白字符变更
内嵌 并排
正在显示 包含 39 行增加 和 38 行删除
kalloc.c
浏览文件 @ 0afd1961
......@@ -108,9 +108,6 @@ kalloc(void)
cprintf("kalloc: out of memory");
kmemprint();
return 0;
#if 0
panic("out of memory");
#endif
}
mtrace_label_register(mtrace_label_block,
......
vm.c
浏览文件 @ 0afd1961
......@@ -247,28 +247,19 @@ freevm(pde_t *pgdir)
kfree((char*)pgdir);
}
struct {
struct vmnode n[1024];
} vmnodes;
struct {
struct vmap m[128];
} vmaps;
struct vmnode *
vmn_alloc(uint npg, uint type)
{
struct vmnode *n = kmalloc(sizeof(struct vmnode));
if (n == 0)
panic("out of vmnodes");
if (n == 0) {
cprintf("out of vmnodes");
return 0;
}
if(npg > NELEM(n->page)) {
panic("vmnode too big\n");
}
for (uint i = 0; i < NELEM(n->page); i++)
n->page[i] = 0;
memset(n, 0, sizeof(struct vmnode));
n->npages = npg;
n->ref = 0;
n->ip = 0;
n->type = type;
return n;
}
......@@ -291,7 +282,10 @@ vmn_allocpg(uint npg)
{
struct vmnode *n = vmn_alloc(npg, EAGER);
if (n == 0) return 0;
if (vmn_doallocpg(n) < 0) return 0; // XXX free n
if (vmn_doallocpg(n) < 0) {
vmn_free(n);
return 0;
}
return n;
}
......@@ -330,7 +324,10 @@ vmn_copy(struct vmnode *n)
}
if (n->page[0]) { // If the first page is present, all of them are present
if (vmn_doallocpg(c) < 0) {
panic("vmn_copy\n");
cprintf("vmn_copy: out of memory\n");
vmn_free(c);
cprintf("return\n");
return 0;
}
for(uint i = 0; i < n->npages; i++) {
memmove(c->page[i], n->page[i], PGSIZE);
......@@ -343,23 +340,22 @@ vmn_copy(struct vmnode *n)
struct vmap *
vmap_alloc(void)
{
for(uint i = 0; i < NELEM(vmaps.m); i++) {
struct vmap *m = &vmaps.m[i];
if(m->alloc == 0 && __sync_bool_compare_and_swap(&m->alloc, 0, 1)) {
for(uint j = 0; j < NELEM(m->e); j++){
m->e[j].n = 0;
m->e[j].va_type = PRIVATE;
m->e[j].lock.name = "vma";
}
m->lock.name = "vmap";
m->ref = 1;
m->pgdir = setupkvm();
if (m->pgdir == 0)
panic("vmap_alloc: setupkvm out of memory");
return m;
}
struct vmap *m = kmalloc(sizeof(struct vmap));
if (m == 0) return 0;
memset(m, 0, sizeof(struct vmap));
for(uint j = 0; j < NELEM(m->e); j++){
m->e[j].va_type = PRIVATE;
m->e[j].lock.name = "vma";
}
return 0;
m->lock.name = "vmap";
m->ref = 1;
m->pgdir = setupkvm();
if (m->pgdir == 0) {
cprintf("vmap_alloc: setupkvm out of memory");
kmfree(m);
return 0;
}
return m;
}
static void
......@@ -492,7 +488,7 @@ vmap_copy(struct vmap *m, int share)
}
if(c->e[i].n == 0) {
release(&m->lock);
vmap_decref(c);
vmap_free(c);
return 0;
}
__sync_fetch_and_add(&c->e[i].n->ref, 1);
......@@ -617,13 +613,17 @@ pagefault_ondemand(struct vmap *vmap, uint va, uint err, struct vma *m)
return m;
}
static void
static int
pagefault_wcow(struct vmap *vmap, uint va, pte_t *pte, struct vma *m, uint npg)
{
// Always make a copy of n, even if this process has the only ref, because other processes
// may change ref count while this process is handling wcow
struct vmnode *o = m->n;
struct vmnode *c = vmn_copy(m->n);
if (c == 0) {
cprintf("pagefault_wcow: out of mem\n");
return -1;
}
c->ref = 1;
m->va_type = PRIVATE;
m->n = c;
......@@ -633,6 +633,7 @@ pagefault_wcow(struct vmap *vmap, uint va, pte_t *pte, struct vma *m, uint npg)
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
// drop my ref to vmnode
vmn_decref(o);
return 0;
}
int
......@@ -650,7 +651,10 @@ pagefault(struct vmap *vmap, uint va, uint err)
m = pagefault_ondemand(vmap, va, err, m);
}
if (m->va_type == COW && (err & FEC_WR)) {
pagefault_wcow(vmap, va, pte, m, npg);
if (pagefault_wcow(vmap, va, pte, m, npg) < 0) {
release(&m->lock);
return -1;
}
} else if (m->va_type == COW) {
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_COW;
} else {
......
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