Remove dead rcu.c

c8f0c10b · Silas Boyd-Wickizer · 0e3b9889 · 0e3b9889
--- a/rcu.c
+++ b/rcu.c
-#include "types.h"
-#include "kernel.h"
-#include "mmu.h"
-#include "amd64.h"
-#include "spinlock.h"
-#include "condvar.h"
-#include "queue.h"
-#include "proc.h"
-#include "cpu.h"
-#include "kmtrace.h"
-struct rcu {
-  unsigned long epoch;
-  TAILQ_ENTRY(rcu) link;
-  union {
-    struct {
-      void (*dofree)(void *);
-      void *item;
-    } f1;
-    struct {
-      void (*dofree)(int, u64);
-      int arg1;
-      u64 arg2;
-    } f2;
-  };
-  int type;
-};
-TAILQ_HEAD(rcu_head, rcu);
-static struct { struct rcu_head x __mpalign__; } rcu_q[NCPU];
-static u64 global_epoch __mpalign__;
-static struct { struct spinlock l __mpalign__; } rcu_lock[NCPU];
-static struct { int v __mpalign__; } delayed_nfree[NCPU];
-static struct { struct condvar cv __mpalign__; } rcu_cv[NCPU];
-enum { rcu_debug = 0 };
-struct rcu *
-rcu_alloc()
-{
-  return kmalloc(sizeof(struct rcu));
-}
-void *
-rcu_min(void *vkey, void *v, void *arg){
-  u64 *min_epoch_p = arg;
-  struct proc *p = (struct proc *) v;
-  if (*min_epoch_p > p->epoch) {
-      *min_epoch_p = p->epoch;
-  }
-  return 0;
-}
-// XXX use atomic instruction to update list (instead of holding lock)
-// lists of lists?
-void
-rcu_gc_work(void)
-{
-  struct rcu *r, *nr;
-  u64 min_epoch = global_epoch;
-  int n = 0;
-  ns_enumerate(nspid, rcu_min, &min_epoch);
-  // pushcli(); // not necessary: rcup->cpu_pin==1
-  acquire(&rcu_lock[mycpu()->id].l);
-  for (r = TAILQ_FIRST(&rcu_q[mycpu()->id].x); r != NULL; r = nr) {
-    if (r->epoch >= min_epoch)
-      break;
-    release(&rcu_lock[mycpu()->id].l);
-    // cprintf("free: %d (%x %x)\n", r->epoch, r->dofree, r->item);
-    switch (r->type) {
-    case 1:
-      r->f1.dofree(r->f1.item);
-      break;
-    case 2:
-      r->f2.dofree(r->f2.arg1, r->f2.arg2);
-      break;
-    default:
-      panic("rcu type");
-    }
-    acquire(&rcu_lock[mycpu()->id].l);
-    delayed_nfree[mycpu()->id].v--;
-    n++;
-    nr = TAILQ_NEXT(r, link);
-    TAILQ_REMOVE(&rcu_q[mycpu()->id].x, r, link);
-    kmfree(r);
-  }
-  release(&rcu_lock[mycpu()->id].l);
-  if (rcu_debug)
-    cprintf("rcu_gc: cpu %d n %d delayed_nfree=%d min_epoch=%d\n",
-	    mycpu()->id, n, delayed_nfree[mycpu()->id], min_epoch);
-  // popcli(); // not necessary: rcup->cpu_pin==1
-  // global_epoch can be bumped anywhere; this seems as good a place as any
-  __sync_fetch_and_add(&global_epoch, 1);
-}
-void
-rcu_gc_worker(void)
-{
-  release(&myproc()->lock);	// initially held by scheduler
-  mtstart(rcu_gc_worker, myproc());
-  struct spinlock wl;
-  initlock(&wl, "rcu_gc_worker");   // dummy lock
-  for (;;) {
-    rcu_gc_work();
-    acquire(&wl);
-    cv_sleep(&rcu_cv[mycpu()->id].cv, &wl);
-    release(&wl);
-  }
-}
-void
-rcu_gc(void)
-{
-  cv_wakeup(&rcu_cv[mycpu()->id].cv);
-}
-// XXX Use atomic instruction to update list (instead of holding lock)
-static void
-rcu_delayed_int(struct rcu *r)
-{
-  pushcli();
-  acquire(&rcu_lock[mycpu()->id].l);
-  // cprintf("rcu_delayed: %d\n", global_epoch);
-  TAILQ_INSERT_TAIL(&rcu_q[mycpu()->id].x, r, link);
-  delayed_nfree[mycpu()->id].v++;
-  release(&rcu_lock[mycpu()->id].l);
-  popcli();
-}
-void
-rcu_delayed(void *e, void (*dofree)(void *))
-{
-  if (rcu_debug)
-    cprintf("rcu_delayed: %x %x\n", dofree, e);
-  struct rcu *r = rcu_alloc();
-  if (r == 0)
-    panic("rcu_delayed");
-  r->f1.dofree = dofree;
-  r->f1.item = e;
-  r->epoch = global_epoch;
-  r->type = 1;
-  rcu_delayed_int(r);
-}
-void
-rcu_delayed2(int a1, u64 a2, void (*dofree)(int,u64))
-{
-  struct rcu *r = rcu_alloc();
-  if (r == 0)
-    panic("rcu_delayed");
-  r->f2.dofree = dofree;
-  r->f2.arg1 = a1;
-  r->f2.arg2 = a2;
-  r->epoch = global_epoch;
-  r->type = 2;
-  rcu_delayed_int(r);
-}
-void
-rcu_begin_read(void)
-{
-  if (myproc() && myproc()->rcu_read_depth++ == 0)
-    myproc()->epoch = global_epoch;
-  __sync_synchronize();
-}
-void
-rcu_end_read(void)
-{
-  if (myproc() && myproc()->rcu_read_depth > 0 &&
-      --myproc()->rcu_read_depth == 0)
-    myproc()->epoch = INF;
-}
-void
-rcu_begin_write(struct spinlock *l)
-{
-  if (l)
-    acquire(l);
-  __sync_synchronize();
-  rcu_begin_read();
-}
-void
-rcu_end_write(struct spinlock *l)
-{
-  rcu_end_read();
-  if (l)
-    release(l);
-}
-void
-initrcu(void)
-{
-  for (int i = 0; i < NCPU; i++) {
-    initlock(&rcu_lock[i].l, "rcu");
-    TAILQ_INIT(&rcu_q[i].x);
-    initcondvar(&rcu_cv[i].cv, "rcu_gc_cv");
-  }
-}