tlb flush barrier, commented out due to C/C++ conflicts

b932ffeb · Nickolai Zeldovich · 73614a93 · b932ffeb · b932ffeb · b932ffeb
--- a/cpu.h
+++ b/cpu.h
 #include "mmu.h"

 struct cilkframe;
+// extern atomic<u64> tlbflush_req;

 // Per-CPU state
 struct cpu {
@@ -12,6 +13,7 @@ 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

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

--- a/hwvm.cc
+++ b/hwvm.cc
@@ -213,3 +213,23 @@ inittls(void)
  c->proc = NULL;
  c->kmem = &kmems[cpunum()];
 }
+
+atomic<u64> tlbflush_req;
+
+void
+tlbflush()
+{
+  // u64 myreq = tlbflush_req++;
+  cli();
+  lcr3(rcr3());
+  for (int i = 0; i < ncpu; i++)
+    if (i != mycpu()->id)
+      lapic_tlbflush(i);
+  sti();
+
+  for (int i = 0; i < ncpu; i++) {
+    if (i != mycpu()->id) {
+      // while (cpus[i].tlbflush_done < myreq) /* spin */ ;
+    }
+  }
+}
--- a/kernel.h
+++ b/kernel.h
@@ -109,6 +109,7 @@ void            freevm(pml4e_t*);
 pml4e_t*        setupkvm(void);
 int             setupkshared(pml4e_t *pml4, char *kshared);
 pme_t *         walkpgdir(pml4e_t*, const void*, int);
+void            tlbflush(void);

 // hz.c
 void            microdelay(u64);

--- a/lapic.cc
+++ b/lapic.cc
@@ -181,7 +181,9 @@ 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/sysproc.cc
+++ b/sysproc.cc
@@ -140,12 +140,7 @@ sys_unmap(void)

  updatepages(myproc()->vmap->pml4,
              (void*) align_addr, (void*) (align_addr+align_len-1), 0);
-  cli();
-  lcr3(v2p(myproc()->vmap->pml4));
-  for (int i = 0; i < ncpu; i++)
-    if (i != mycpu()->id)
-      lapic_tlbflush(i);
-  sti();
+  tlbflush();
  return 0;
 }


--- a/trap.c
+++ b/trap.c
@@ -113,8 +113,10 @@ trap(struct trapframe *tf)
            mycpu()->id, tf->cs, tf->rip);
    lapiceoi();
  case T_TLBFLUSH:
+    // nreq = tlbflush_req.load();
    lapiceoi();
    lcr3(rcr3());
+    // mycpu()->tlbflush_done = nreq;
    break;
  case T_SAMPCONF:
    lapiceoi();