real tlb flush barrier

e0780ce4 · Nickolai Zeldovich · f336c8cd · e0780ce4 · e0780ce4 · e0780ce4
--- a/cpu.hh
+++ b/cpu.hh
 #include "mmu.h"
+#include "atomic.hh"

 struct cilkframe;
-// extern atomic<u64> tlbflush_req;
+using std::atomic;
+
+extern atomic<u64> tlbflush_req;

 // Per-CPU state
 struct cpu {
@@ -13,7 +16,7 @@ struct cpu {
  struct context *scheduler;   // swtch() here to enter scheduler
  struct cilkframe *cilkframe;
  int timer_printpc;
-  // atomic<u64> tlbflush_done;   // last tlb flush req done on this cpu
+  atomic<u64> tlbflush_done;   // last tlb flush req done on this cpu

  // Cpu-local storage variables; see below
  struct cpu *cpu;

--- a/hwvm.cc
+++ b/hwvm.cc
@@ -216,17 +216,18 @@ atomic<u64> tlbflush_req;
 void
 tlbflush()
 {
-  // u64 myreq = tlbflush_req++;
+  u64 myreq = tlbflush_req++;
+
  cli();
+  int myid = mycpu()->id;
  lcr3(rcr3());
  for (int i = 0; i < ncpu; i++)
-    if (i != mycpu()->id)
+    if (i != myid)
      lapic_tlbflush(i);
  sti();

-  for (int i = 0; i < ncpu; i++) {
-    if (i != mycpu()->id) {
-      // while (cpus[i].tlbflush_done < myreq) /* spin */ ;
-    }
-  }
+  for (int i = 0; i < ncpu; i++)
+    if (i != myid)
+      while (cpus[i].tlbflush_done < myreq)
+        /* spin */ ;
 }
--- a/lapic.cc
+++ b/lapic.cc
@@ -6,6 +6,7 @@
 #include "kernel.hh"
 #include "traps.h"
 #include "bits.h"
+#include "cpu.hh"

 // Local APIC registers, divided by 4 for use as uint[] indices.
 #define ID      (0x0020/4)   // ID
@@ -179,9 +180,7 @@ lapic_ipi(int cpu, int ino)
 void
 lapic_tlbflush(u32 cpu)
 {
-  cprintf("lapic_tlbflush: to cpu %d\n", cpu);
  lapic_ipi(cpu, T_TLBFLUSH);
-  cprintf("lapic_tlbflush: to cpu %d done\n", cpu);
 }

 void

--- a/mapbench.cc
+++ b/mapbench.cc
@@ -14,7 +14,7 @@ thr(void *arg)
 {
  u64 tid = (u64)arg;

-  for (int i = 0; i < 10000; i++) {
+  for (int i = 0; i < 1000; i++) {
    volatile char *p = (char*) (0x40000UL + tid * 8 * 4096);
    if (map((void *) p, 8 * 4096) < 0) {
      printf(1, "%d: map failed\n", tid);

--- a/trap.cc
+++ b/trap.cc
@@ -95,12 +95,13 @@ trap(struct trapframe *tf)
    cprintf("cpu%d: spurious interrupt at %x:%lx\n",
            mycpu()->id, tf->cs, tf->rip);
    lapiceoi();
-  case T_TLBFLUSH:
-    // nreq = tlbflush_req.load();
+  case T_TLBFLUSH: {
+    u64 nreq = tlbflush_req.load();
    lapiceoi();
    lcr3(rcr3());
-    // mycpu()->tlbflush_done = nreq;
+    mycpu()->tlbflush_done = nreq;
    break;
+  }
  case T_SAMPCONF:
    lapiceoi();
    sampconf();