use wait() in mapbench instead of spinning

6d913c9f · Nickolai Zeldovich · 30cd42f6 · 6d913c9f
--- a/bin/mapbench.cc
+++ b/bin/mapbench.cc
@@ -5,8 +5,6 @@
 #include "amd64.h"
 #include "uspinlock.h"

-static struct uspinlock l;
-static volatile int tcount;
 enum { readaccess = 0 };
 enum { verbose = 0 };
 enum { npg = 1 };
@@ -36,11 +34,6 @@ thr(void *arg)
      exit();
    }
  }
-
-  acquire(&l);
-  // fprintf(1, "mapbench[%d]: done\n", getpid());
-  tcount++;
-  release(&l);
 }

 int
@@ -55,7 +48,6 @@ main(int ac, char **av)

  int nthread = atoi(av[1]);

-  acquire(&l);
  // fprintf(1, "mapbench[%d]: start esp %x, nthread=%d\n", getpid(), rrsp(), nthread);

  for(int i = 0; i < nthread; i++) {
@@ -66,22 +58,10 @@ main(int ac, char **av)
    if (0) fprintf(1, "mapbench[%d]: child %d\n", getpid(), tid);
  }

-  for(;;){
-    int lastc = tcount;
-    // fprintf(1, "mapbench[%d]: tcount=%d\n", getpid(), lastc);
-    release(&l);
-    if(lastc==nthread)
-      break;
-    while(tcount==lastc)
-      __asm __volatile("":::"memory");
-    acquire(&l);
-  }
-  release(&l);
-  // fprintf(1, "mapbench[%d]: done\n", getpid());
-
  for(int i = 0; i < nthread; i++)
    wait();

+  // fprintf(1, "mapbench[%d]: done\n", getpid());
  mtdisable("xv6-mapbench");
  // halt();
  exit();