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提交 58bb7de1 创建 作者: Nickolai Zeldovich's avatar Nickolai Zeldovich
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entire vma is now const -- no need for a lock

上级 a3649f33
隐藏空白字符变更
内嵌 并排
正在显示 包含 7 行增加 和 31 行删除
include/vm.hh
浏览文件 @ 58bb7de1
...@@ -37,8 +37,6 @@ struct vma : public range { ...@@ -37,8 +37,6 @@ struct vma : public range {
const uptr vma_end; // one past the last byte const uptr vma_end; // one past the last byte
const enum vmatype va_type; const enum vmatype va_type;
struct vmnode * const n; struct vmnode * const n;
struct spinlock lock; // serialize fault/unmap
char lockname[16];
vma(vmap *vmap, uptr start, uptr end, enum vmatype vtype, vmnode *vmn); vma(vmap *vmap, uptr start, uptr end, enum vmatype vtype, vmnode *vmn);
~vma(); ~vma();
...@@ -72,6 +70,5 @@ struct vmap { ...@@ -72,6 +70,5 @@ struct vmap {
int copyout(uptr va, void *p, u64 len); int copyout(uptr va, void *p, u64 len);
private: private:
vma* pagefault_ondemand(uptr va, vma *m, scoped_acquire *mlock);
int pagefault_wcow(vma *m); int pagefault_wcow(vma *m);
}; };
kernel/vm.cc
浏览文件 @ 58bb7de1
...@@ -125,15 +125,12 @@ vma::vma(vmap *vmap, uptr start, uptr end, enum vmatype vtype, vmnode *vmn) ...@@ -125,15 +125,12 @@ vma::vma(vmap *vmap, uptr start, uptr end, enum vmatype vtype, vmnode *vmn)
{ {
if (n) if (n)
n->ref++; n->ref++;
snprintf(lockname, sizeof(lockname), "vma:%p", this);
initlock(&lock, lockname, LOCKSTAT_VM);
} }
vma::~vma() vma::~vma()
{ {
if (n) if (n)
n->decref(); n->decref();
destroylock(&lock);
} }
/* /*
...@@ -215,10 +212,8 @@ vmap::copy(int share) ...@@ -215,10 +212,8 @@ vmap::copy(int share)
for (range *r: cr) { for (range *r: cr) {
vma *e = (vma *) r; vma *e = (vma *) r;
scoped_acquire sae(&e->lock);
struct vma *ne; struct vma *ne;
if (share) { if (share) {
ne = new vma(nm, e->vma_start, e->vma_end, COW, e->n); ne = new vma(nm, e->vma_start, e->vma_end, COW, e->n);
...@@ -368,21 +363,6 @@ vmap::remove(uptr vma_start, uptr len) ...@@ -368,21 +363,6 @@ vmap::remove(uptr vma_start, uptr len)
* pagefault handling code on vmap * pagefault handling code on vmap
*/ */
vma *
vmap::pagefault_ondemand(uptr va, vma *m, scoped_acquire *mlock)
{
if (m->n->allocpg() < 0)
panic("pagefault: couldn't allocate pages");
mlock->release();
if (m->n->demand_load() < 0)
panic("pagefault: couldn't load");
m = lookup(va, 1);
if (!m)
panic("pagefault_ondemand");
mlock->acquire(&m->lock); // re-acquire lock on m
return m;
}
int int
vmap::pagefault_wcow(vma *m) vmap::pagefault_wcow(vma *m)
{ {
...@@ -435,21 +415,22 @@ vmap::pagefault(uptr va, u32 err) ...@@ -435,21 +415,22 @@ vmap::pagefault(uptr va, u32 err)
if (m == 0) if (m == 0)
return -1; return -1;
scoped_acquire mlock(&m->lock);
u64 npg = (PGROUNDDOWN(va) - m->vma_start) / PGSIZE; u64 npg = (PGROUNDDOWN(va) - m->vma_start) / PGSIZE;
if (m->n && m->n->type == ONDEMAND && m->n->page[npg] == 0)
m = pagefault_ondemand(va, m, &mlock);
if (vm_debug) if (vm_debug)
cprintf("pagefault: err 0x%x va 0x%lx type %d ref %lu pid %d\n", cprintf("pagefault: err 0x%x va 0x%lx type %d ref %lu pid %d\n",
err, va, m->va_type, m->n->ref.load(), myproc()->pid); err, va, m->va_type, m->n->ref.load(), myproc()->pid);
if (m->n && m->n->type == ONDEMAND && m->n->page[npg] == 0) {
if (m->n->allocpg() < 0)
panic("pagefault: couldn't allocate pages");
if (m->n->demand_load() < 0)
panic("pagefault: couldn't load");
}
if (m->va_type == COW && (err & FEC_WR)) { if (m->va_type == COW && (err & FEC_WR)) {
if (pagefault_wcow(m) < 0) if (pagefault_wcow(m) < 0)
return -1; return -1;
mlock.release();
tlbflush(); tlbflush();
goto retry; goto retry;
} }
...@@ -491,7 +472,6 @@ vmap::copyout(uptr va, void *p, u64 len) ...@@ -491,7 +472,6 @@ vmap::copyout(uptr va, void *p, u64 len)
if(vma == 0) if(vma == 0)
return -1; return -1;
acquire(&vma->lock);
uptr pn = (va0 - vma->vma_start) / PGSIZE; uptr pn = (va0 - vma->vma_start) / PGSIZE;
char *p0 = vma->n->page[pn]; char *p0 = vma->n->page[pn];
if(p0 == 0) if(p0 == 0)
...@@ -503,7 +483,6 @@ vmap::copyout(uptr va, void *p, u64 len) ...@@ -503,7 +483,6 @@ vmap::copyout(uptr va, void *p, u64 len)
len -= n; len -= n;
buf += n; buf += n;
va = va0 + PGSIZE; va = va0 + PGSIZE;
release(&vma->lock);
} }
return 0; return 0;
} }
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