disable-log-before-main.patch

don't spawn new threads before main

From: Aaron Jones <aaron@vexing.codes>

The function haveSse42 is called at static initialization time. When LOG is
called it will call RAMCloud::Logger::get which will instantiate a static
RAMCloud::Logger instance which spawns a thread
(RAMCloud::Logger::printThreadMain). This thread is spawned before we have a
chance to block signals in it, so the logging thread will intercept signals we
want to handle with our own signal handling thread in
stateless::kernel::signal_handler. To avoid printThreadMain starting before main
we comment out the lines in haveSse42 that invoke LOG.
---
 src/Crc32C.cc |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Crc32C.cc b/src/Crc32C.cc
index 4bfb47a2..0f3ef486 100644
--- a/src/Crc32C.cc
+++ b/src/Crc32C.cc
@@ -30,10 +30,12 @@ haveSse42() {
     uint32_t a, b, c, d;
     CPUID(1, a, b, c, d);
     bool ret = ((c & (1 << 20)) != 0);
+#if 0
     if (ret)
         LOG(DEBUG, "Processor has SSE 4.2");
     else
         LOG(DEBUG, "Processor does not have SSE 4.2");
+#endif
     return ret;
 }
 } // anonymous namespace