diff options
| author | Henning Baldersheim <balder@yahoo-inc.com> | 2020-04-21 07:43:04 +0000 |
|---|---|---|
| committer | Henning Baldersheim <balder@yahoo-inc.com> | 2020-04-21 07:43:04 +0000 |
| commit | aea517d7ee398198bff1f8cfd773c633ae4de80f (patch) | |
| tree | 184c4a38050e197067046ffb2b426551a3626333 /vespalib | |
| parent | 0b37ff6b24dc51e5100ca1843b104f71d5363341 (diff) | |
Elaborate a bit more in the comment.
Diffstat (limited to 'vespalib')
| -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 { |