Eliminate an integer division in trace_return().

bolinfest · Sep 21, 2018 · afa0e91 · afa0e91
1 parent 5b7968a
commit afa0e91
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/opensnoop/opensnoop.c b/opensnoop/opensnoop.c
@@ -265,6 +265,7 @@ void printHeader() {
 }
 
 long long initialTimestamp = 0;
+const float NANOS_PER_SECOND = 1000000000;
 void perf_reader_raw_callback(void *cb_cookie, void *raw, int raw_size) {
   struct data_t *event = (struct data_t *)raw;
   if (opt_failed && event->ret >= 0) {
@@ -290,7 +291,7 @@ void perf_reader_raw_callback(void *cb_cookie, void *raw, int raw_size) {
     }
 
     long long delta = event->ts - initialTimestamp;
-    printf("%-14.9f", ((float) delta) / 1000000);
+    printf("%-14.9f", delta / NANOS_PER_SECOND);
   }
 
   int pid = event->id >> 32;

diff --git a/opensnoop/opensnoop.py b/opensnoop/opensnoop.py
@@ -65,7 +65,7 @@
     bpf_probe_read(&data.comm, sizeof(data.comm), valp->comm);
     bpf_probe_read(&data.fname, sizeof(data.fname), (void *)valp->fname);
     data.id = valp->id;
-    data.ts = tsp / 1000;
+    data.ts = tsp;
     data.ret = PT_REGS_RC(ctx);
 
     events.perf_submit(ctx, &data, sizeof(data));