diff options
| -rw-r--r-- | vespalib/src/vespa/vespalib/util/time.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/vespalib/src/vespa/vespalib/util/time.cpp b/vespalib/src/vespa/vespalib/util/time.cpp index 2e8f4e7e30e..61a295c6dc3 100644 --- a/vespalib/src/vespa/vespalib/util/time.cpp +++ b/vespalib/src/vespa/vespalib/util/time.cpp @@ -55,8 +55,13 @@ Timer::waitAtLeast(duration dur, bool busyWait) { namespace std::chrono { -// This is a hack to avoid the slow clock computations on RHEL7/CentOS 7 due to using systemcalls. -// This brings cost down from 550-560ns to 18-19ns +/* + * This is a hack to avoid the slow clock computations on RHEL7/CentOS 7 due to using systemcalls. + * This brings cost down from 550-560ns to 18-19ns on a Intel Haswell 2680 cpu. + * We are providing the symbols here so they will take precedence over the ones in the standard library. + * We rely on the linker do handle correct symbol resolution. + * TODO: Once we are off the ancient platforms like Centos 7/ Rhel 7 we can drop this workaround. +*/ inline namespace _V2 { |