Experiment for updating the tcmalloc chromium branch to r144 (gperftools 2.0).

third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h

Index: third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h
diff --git a/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h b/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h
index dc2c6bac4d8c5384e065587fd7277dd8a9bb8ee4..c190d525aa6bc5efecf3a307f71c5c182555d721 100644
--- a/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h
+++ b/third_party/tcmalloc/chromium/src/base/spinlock_linux-inl.h
@@ -31,6 +31,7 @@
  * This file is a Linux-specific part of spinlock_internal.cc
  */
 
+#include <errno.h>
 #include <sched.h>
 #include <time.h>
 #include <limits.h>
@@ -86,12 +87,12 @@ void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop) {
     struct timespec tm;
     tm.tv_sec = 0;
     if (have_futex) {
-      tm.tv_nsec = 1000000;   // 1ms; really we're trying to sleep for one
-                              // kernel clock tick
+      tm.tv_nsec = base::internal::SuggestedDelayNS(loop);
     } else {
       tm.tv_nsec = 2000001;   // above 2ms so linux 2.4 doesn't spin
     }
     if (have_futex) {
+      tm.tv_nsec *= 16;  // increase the delay; we expect explicit wakeups
       syscall(__NR_futex, reinterpret_cast<int *>(const_cast<Atomic32 *>(w)),
                 FUTEX_WAIT | futex_private_flag,
                 value, reinterpret_cast<struct kernel_timespec *>(&tm));