Pull proclock apart: condition vars, per process lock, runq lock

Passes forktest w. 2 CPUs

Pull proclock apart: condition vars, per process lock, runq lock
1403faf4 · Frans Kaashoek · 3bf5e592 · 1403faf4 · 1403faf4 · 1403faf4
--- a/proc.c
+++ b/proc.c
--- a/proc.h
+++ b/proc.h
@@ -45,6 +45,7 @@ struct proc {
  struct file *ofile[NOFILE];  // Open files
  struct inode *cwd;           // Current directory
  char name[16];               // Process name (debugging)
+  struct spinlock lock;
  struct proc *next;
 };

@@ -69,6 +70,18 @@ struct cpu {
  struct proc *proc;           // The currently-running process.
  struct ptable *ptable;       // The per-core proc table
  struct kmem *kmem;           // The per-core proc table
+  struct runq *runq;           // The per-core proc table
+};
+
+struct condvar {
+  void *chan;                  // If non-zero, sleeping on chan
+  struct proc *waiters;
+};
+
+struct runq {
+  char name[MAXNAME];
+  struct spinlock lock;
+  struct proc *runq;
 };

 struct ptable {
@@ -80,6 +93,7 @@ struct ptable {

 extern struct ptable ptables[NCPU];
 extern struct cpu cpus[NCPU];
+extern struct runq runqs[NCPU];
 extern int ncpu;

 // Per-CPU variables, holding pointers to the
@@ -94,3 +108,4 @@ extern struct cpu *cpu asm("%gs:0");       // &cpus[cpunum()]
 extern struct proc *proc asm("%gs:4");     // cpus[cpunum()].proc
 extern struct ptable *ptable asm("%gs:8"); // &ptables[cpunum()]
 extern struct kmem *kmem asm("%gs:12"); // &kmems[cpunum()]
+extern struct runq *runq asm("%gs:16"); // &runqs[cpunum()]
--- a/spinlock.c
+++ b/spinlock.c
@@ -24,8 +24,10 @@ void
 acquire(struct spinlock *lk)
 {
  pushcli(); // disable interrupts to avoid deadlock.
-  if(holding(lk))
+  if(holding(lk)) {
+    cprintf("lock: %s\n", lk->name);
    panic("acquire");
+  }

  // The xchg is atomic.
  // It also serializes, so that reads after acquire are not
@@ -42,8 +44,10 @@ acquire(struct spinlock *lk)
 void
 release(struct spinlock *lk)
 {
-  if(!holding(lk))
+  if(!holding(lk)) {
+    cprintf("lock: %s\n", lk->name);
    panic("release");
+  }

  lk->pcs[0] = 0;
  lk->cpu = 0;

--- a/vm.c
+++ b/vm.c
@@ -37,8 +37,8 @@ seginit(void)
  c->gdt[SEG_UCODE] = SEG(STA_X|STA_R, 0, 0xffffffff, DPL_USER);
  c->gdt[SEG_UDATA] = SEG(STA_W, 0, 0xffffffff, DPL_USER);

-  // Map cpu, curproc, ptable, kmem
-  c->gdt[SEG_KCPU] = SEG(STA_W, &c->cpu, 16, 0);
+  // Map cpu, curproc, ptable, kmem, runq
+  c->gdt[SEG_KCPU] = SEG(STA_W, &c->cpu, 20, 0);

  lgdt(c->gdt, sizeof(c->gdt));
  loadgs(SEG_KCPU << 3);
@@ -48,6 +48,7 @@ seginit(void)
  proc = 0;
  ptable = &ptables[cpunum()];
  kmem = &kmems[cpunum()];
+  runq = &runqs[cpunum()];
 }

 // Return the address of the PTE in page table pgdir