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xv6-public
提交 d1f78e45 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 731ffe8e 18c0f586
隐藏空白字符变更
内嵌 并排
正在显示 包含 20 行增加 和 21 行删除
param.h
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......@@ -8,7 +8,7 @@
#define NDEV 10 // maximum major device number
#define ROOTDEV 1 // device number of file system root disk
#define USERTOP 0xA0000 // end of user address space
#define PHYSTOP 0x4000000 // use phys mem up to here as free pool
#define PHYSTOP 0x1000000 // use phys mem up to here as free pool
#define MAXARG 32 // max exec arguments
#define MAXNAME 16 // max string names
#define MINCYCTHRESH 1000000 // min cycles a proc executes on a core before allowed to be stolen
proc.c
浏览文件 @ d1f78e45
......@@ -261,7 +261,7 @@ fork(int flags)
{
int i, pid;
struct proc *np;
uint cow = 0;
uint cow = 1;
// cprintf("%d: fork\n", proc->pid);
......
vm.c
浏览文件 @ d1f78e45
......@@ -369,9 +369,10 @@ vmap_alloc(void)
static void
vmap_free(struct vmap *m)
{
for(uint i = 0; i < sizeof(m->e) / sizeof(m->e[0]); i++)
for(uint i = 0; i < sizeof(m->e) / sizeof(m->e[0]); i++) {
if(m->e[i].n)
vmn_decref(m->e[i].n);
}
freevm(m->pgdir);
m->pgdir = 0;
m->alloc = 0;
......@@ -449,7 +450,7 @@ vmap_remove(struct vmap *m, uint va_start, uint len)
return -1;
}
__sync_fetch_and_sub(&m->e[i].n->ref, 1);
__sync_fetch_and_sub(&m->e[i].n->ref, 1); // XXX shouldn't use vmn_decref?
m->e[i].n = 0;
}
}
......@@ -624,22 +625,19 @@ pagefault_ondemand(struct vmap *vmap, uint va, uint err, struct vma *m)
static void
pagefault_wcow(struct vmap *vmap, uint va, pte_t *pte, struct vma *m, uint npg)
{
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;
} else { // vma is still shared; give process its private copy
struct vmnode *c = vmn_copy(m->n);
c->ref = 1;
__sync_sub_and_fetch(&m->n->ref, 1);
if (m->n->ref == 0)
panic("cow");
m->va_type = PRIVATE;
m->n = c;
// Update the hardware page tables to reflect the change to the vma
clearpages(vmap->pgdir, (void *) m->va_start, (void *) m->va_end);
pte = walkpgdir(vmap->pgdir, (const void *)va, 0);
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
}
// 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);
c->ref = 1;
m->va_type = PRIVATE;
m->n = c;
// Update the hardware page tables to reflect the change to the vma
clearpages(vmap->pgdir, (void *) m->va_start, (void *) m->va_end);
pte = walkpgdir(vmap->pgdir, (const void *)va, 0);
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
// drop my ref to vmnode
vmn_decref(o);
}
int
......@@ -661,8 +659,9 @@ pagefault(struct vmap *vmap, uint va, uint err)
} else if (m->va_type == COW) {
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_COW;
} else {
if (m->n->ref > 1)
if (m->n->ref != 1) {
panic("pagefault");
}
*pte = PADDR(m->n->page[npg]) | PTE_P | PTE_U | PTE_W;
}
lcr3(PADDR(vmap->pgdir)); // Reload hardware page tables
......
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