schedbench tweaks

10a81148 · Silas Boyd-Wickizer · 4a23dff8 · 10a81148
--- a/bin/schedbench.cc
+++ b/bin/schedbench.cc
@@ -5,11 +5,13 @@
 #include "futex.h"
 #include "errno.h"
 #include "atomic.hh"
+#include "mtrace.h"

 static volatile std::atomic<u64> waiting;
 static volatile std::atomic<u64> waking;
 static int iters;
 static int nworkers;
+static volatile int go;

 static struct {
  u64 mem;
@@ -24,6 +26,11 @@ void* worker0(void* x)
  u64* f = &(ftx[id>>1].mem);
  long r;

+  setaffinity(id);
+
+  while (go == 0)
+    yield();
+
  if (id & 0x1) {
    for (u64 i = 0; i < iters; i++) {
      r = futex(f, FUTEX_WAIT, (u64)(i<<1), 0);
@@ -50,6 +57,7 @@ void* worker0(void* x)
 static
 void master0(void)
 {
+  go = 1;
  for (int i = 0; i < nworkers; i++)
    wait();
 }
@@ -75,9 +83,11 @@ main(int ac, char** av)
  }
  nsleep(1000*1000);

+  mtenable("xv6-schedbench");
  u64 t0 = rdtsc();
  master0();
  u64 t1 = rdtsc();
+  mtdisable("xv6-schedbench");
  printf("%lu\n", (t1-t0)/iters);
 }