profile cycles spent in arc4 -- appears to be less than 2%.

53275c83 · Nickolai Zeldovich · 5f8ad95c · 53275c83
--- a/user/umain.cc
+++ b/user/umain.cc
@@ -11,7 +11,11 @@
 #include "intelctr.hh"
 #include "arc4.hh"
 #include "amd64.h"
-#include "rnd.hh"
+
+static auto perfgroup = ctrgroup(&intelctr::tsc
+                                // ,&intelctr::l2_refs
+                                // ,&intelctr::l2_miss
+                                );

 u64
 proc_hash(const u32 &pid)
@@ -25,9 +29,13 @@ u32 ncpu;
 u64 ticks;
 xns<u32, proc*, proc_hash> *xnspid;

+static auto rnd_perfsum = scopedperf::perfsum("arc4 rnd", &perfgroup);
+
 template<class T>
 T rnd()
 {
+  auto __PERF_ANON = scopedperf::perf_region(&rnd_perfsum);
+
  arc4 *a = (arc4*) pthread_getspecific(arc4_key);
  if (!a) {
    struct seed { u64 a, b; } s = { rdtsc(), pthread_self() };
@@ -77,11 +85,6 @@ static pthread_barrier_t worker_b, populate_b;
 enum { iter_total = 1000000 };
 enum { crange_items = 1024 };

-static auto perfgroup = ctrgroup(&intelctr::tsc
-                                // ,&intelctr::l2_refs
-                                // ,&intelctr::l2_miss
-                                );
-
 static void
 worker(void *arg)
 {