forktree workload

b11c28b9 · Nickolai Zeldovich · 2c8b0cbe · b11c28b9 · b11c28b9 · b11c28b9
--- a/Makefile
+++ b/Makefile
@@ -181,6 +181,7 @@ UPROGS=\
 	_thrtest\
 	_sleep\
 	_maptest\
+	_forktree\
 fs.img: mkfs README $(UPROGS)
 	./mkfs fs.img README $(UPROGS)

--- a/forktree.c
+++ b/forktree.c
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+#include "xv6-mtrace.h"
+#define NCHILD 2
+#define NDEPTH 6
+char*
+strncpy(char *s, const char *t, int n)
+{
+  int tlen = strlen((char *)t);
+  memmove(s, (char *)t, n > tlen ? tlen : n);
+  if (n > tlen)
+    s[tlen] = 0;
+  return s;
+}
+void*
+memcpy(void *dst, const void *src, uint n)
+{
+  return memmove(dst, (void *)src, n);
+}
+void
+forktree(void)
+{
+  uint depth = 0;
+  printf(1, "fork tree\n");
+  mtrace_enable_set(1, "xv6-forktree");
+ next_level:
+  //printf(1, "pid %d, depth %d\n", getpid(), depth);
+  if (depth >= NDEPTH)
+    exit();
+  for (uint i = 0; i < NCHILD; i++) {
+    int pid = fork(0);
+    if (pid < 0) {
+      printf(1, "fork error\n");
+      exit();
+    }
+    if (pid == 0) {
+      depth++;
+      goto next_level;
+    }
+  }
+  for (uint i = 0; i < NCHILD; i++) {
+    if (wait() < 0) {
+      printf(1, "wait stopped early\n");
+      exit();
+    }
+  }
+  if (wait() != -1) {
+    printf(1, "wait got too many\n");
+    exit();
+  }
+  if (depth > 0)
+    exit();
+  struct mtrace_appdata_entry entry;
+  entry.u64 = 0;
+  mtrace_appdata_register(&entry);
+  mtrace_enable_set(0, "xv6-forktree");
+  printf(1, "fork tree OK\n");
+  halt();
+}
+int
+main(void)
+{
+  forktree();
+  exit();
+}
--- a/param.h
+++ b/param.h
@@ -8,7 +8,7 @@
 #define NDEV         10  // maximum major device number
 #define ROOTDEV       1  // device number of file system root disk
 #define USERTOP  0xA0000 // end of user address space
-#define PHYSTOP  0x1000000 // use phys mem up to here as free pool
+#define PHYSTOP  0x10000000 // use phys mem up to here as free pool
 #define MAXARG       32  // max exec arguments
 #define MAXNAME      16  // max string names
 #define MINCYCTHRESH 1000000  // min cycles a proc executes on a core before allowed to be stolen