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提交 589f4656 创建 作者: Nickolai Zeldovich's avatar Nickolai Zeldovich
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no need to acquire vmap->lock; seems to work fine without it

上级 f8d394aa
隐藏空白字符变更
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正在显示 包含 0 行增加 和 11 行删除
vm.c
浏览文件 @ 589f4656
...@@ -650,16 +650,13 @@ copyout(struct vmap *vmap, uint va, void *p, uint len) ...@@ -650,16 +650,13 @@ copyout(struct vmap *vmap, uint va, void *p, uint len)
while(len > 0){ while(len > 0){
uint va0 = (uint)PGROUNDDOWN(va); uint va0 = (uint)PGROUNDDOWN(va);
rcu_begin_read(); rcu_begin_read();
acquire(&vmap->lock);
struct vma *vma = vmap_overlap(vmap, va, 1); struct vma *vma = vmap_overlap(vmap, va, 1);
if(vma == 0) { if(vma == 0) {
release(&vmap->lock);
rcu_end_read(); rcu_end_read();
return -1; return -1;
} }
acquire(&vma->lock); acquire(&vma->lock);
release(&vmap->lock);
uint pn = (va0 - vma->va_start) / PGSIZE; uint pn = (va0 - vma->va_start) / PGSIZE;
char *p0 = vma->n->page[pn]; char *p0 = vma->n->page[pn];
if(p0 == 0) if(p0 == 0)
...@@ -684,16 +681,13 @@ copyin(struct vmap *vmap, uint va, void *p, uint len) ...@@ -684,16 +681,13 @@ copyin(struct vmap *vmap, uint va, void *p, uint len)
while(len > 0){ while(len > 0){
uint va0 = (uint)PGROUNDDOWN(va); uint va0 = (uint)PGROUNDDOWN(va);
rcu_begin_read(); rcu_begin_read();
acquire(&vmap->lock);
struct vma *vma = vmap_overlap(vmap, va, 1); struct vma *vma = vmap_overlap(vmap, va, 1);
if(vma == 0) { if(vma == 0) {
release(&vmap->lock);
rcu_end_read(); rcu_end_read();
return -1; return -1;
} }
acquire(&vma->lock); acquire(&vma->lock);
release(&vmap->lock);
uint pn = (va0 - vma->va_start) / PGSIZE; uint pn = (va0 - vma->va_start) / PGSIZE;
char *p0 = vma->n->page[pn]; char *p0 = vma->n->page[pn];
if(p0 == 0) if(p0 == 0)
...@@ -721,12 +715,10 @@ pagefault_ondemand(struct vmap *vmap, uint va, uint err, struct vma *m) ...@@ -721,12 +715,10 @@ pagefault_ondemand(struct vmap *vmap, uint va, uint err, struct vma *m)
if (vmn_doload(m->n, m->n->ip, m->n->offset, m->n->sz) < 0) { if (vmn_doload(m->n, m->n->ip, m->n->offset, m->n->sz) < 0) {
panic("pagefault: couldn't load"); panic("pagefault: couldn't load");
} }
acquire(&vmap->lock);
m = vmap_overlap(vmap, va, 1); m = vmap_overlap(vmap, va, 1);
if (!m) if (!m)
panic("pagefault_ondemand"); panic("pagefault_ondemand");
acquire(&m->lock); // re-acquire lock on m acquire(&m->lock); // re-acquire lock on m
release(&vmap->lock);
return m; return m;
} }
...@@ -761,16 +753,13 @@ pagefault(struct vmap *vmap, uint va, uint err) ...@@ -761,16 +753,13 @@ pagefault(struct vmap *vmap, uint va, uint err)
return 0; return 0;
rcu_begin_read(); rcu_begin_read();
acquire(&vmap->lock);
struct vma *m = vmap_overlap(vmap, va, 1); struct vma *m = vmap_overlap(vmap, va, 1);
if(m == 0) { if(m == 0) {
release(&vmap->lock);
rcu_end_read(); rcu_end_read();
return -1; return -1;
} }
acquire(&m->lock); acquire(&m->lock);
release(&vmap->lock);
uint npg = (PGROUNDDOWN(va) - m->va_start) / PGSIZE; uint npg = (PGROUNDDOWN(va) - m->va_start) / PGSIZE;
if (m->n && m->n->type == ONDEMAND && m->n->page[npg] == 0) { if (m->n && m->n->type == ONDEMAND && m->n->page[npg] == 0) {
m = pagefault_ondemand(vmap, va, err, m); m = pagefault_ondemand(vmap, va, err, m);
......
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