diff options
| -rw-r--r-- | lib/xray/xray_fdr_logging.cc | 13 | ||||
| -rw-r--r-- | lib/xray/xray_inmemory_log.cc | 10 | ||||
| -rw-r--r-- | lib/xray/xray_x86_64.cc | 6 |
3 files changed, 23 insertions, 6 deletions
diff --git a/lib/xray/xray_fdr_logging.cc b/lib/xray/xray_fdr_logging.cc index c5b63b0a5..e538b477a 100644 --- a/lib/xray/xray_fdr_logging.cc +++ b/lib/xray/xray_fdr_logging.cc @@ -118,11 +118,15 @@ XRayLogFlushStatus fdrLoggingFlush() XRAY_NEVER_INSTRUMENT { return Result; } + // Test for required CPU features and cache the cycle frequency + static bool TSCSupported = probeRequiredCPUFeatures(); + static uint64_t CycleFrequency = TSCSupported ? getTSCFrequency() + : __xray::NanosecondsPerSecond; + XRayFileHeader Header; Header.Version = 1; Header.Type = FileTypes::FDR_LOG; - Header.CycleFrequency = probeRequiredCPUFeatures() - ? getTSCFrequency() : __xray::NanosecondsPerSecond; + Header.CycleFrequency = CycleFrequency; // FIXME: Actually check whether we have 'constant_tsc' and 'nonstop_tsc' // before setting the values in the header. Header.ConstantTSC = 1; @@ -196,7 +200,10 @@ void fdrLoggingHandleArg0(int32_t FuncId, unsigned char CPU; uint64_t TSC; - if(probeRequiredCPUFeatures()) { + // Test once for required CPU features + static bool TSCSupported = probeRequiredCPUFeatures(); + + if(TSCSupported) { TSC = __xray::readTSC(CPU); } else { // FIXME: This code needs refactoring as it appears in multiple locations diff --git a/lib/xray/xray_inmemory_log.cc b/lib/xray/xray_inmemory_log.cc index cdaa6d1b5..83aecfaf7 100644 --- a/lib/xray/xray_inmemory_log.cc +++ b/lib/xray/xray_inmemory_log.cc @@ -79,15 +79,19 @@ static int __xray_OpenLogFile() XRAY_NEVER_INSTRUMENT { int F = getLogFD(); if (F == -1) return -1; + + // Test for required CPU features and cache the cycle frequency + static bool TSCSupported = probeRequiredCPUFeatures(); + static uint64_t CycleFrequency = TSCSupported ? getTSCFrequency() + : __xray::NanosecondsPerSecond; + // Since we're here, we get to write the header. We set it up so that the // header will only be written once, at the start, and let the threads // logging do writes which just append. XRayFileHeader Header; Header.Version = 1; Header.Type = FileTypes::NAIVE_LOG; - Header.CycleFrequency = probeRequiredCPUFeatures() - ? getTSCFrequency() - : __xray::NanosecondsPerSecond; + Header.CycleFrequency = CycleFrequency; // FIXME: Actually check whether we have 'constant_tsc' and 'nonstop_tsc' // before setting the values in the header. diff --git a/lib/xray/xray_x86_64.cc b/lib/xray/xray_x86_64.cc index 8c2a4e313..2e9a8d270 100644 --- a/lib/xray/xray_x86_64.cc +++ b/lib/xray/xray_x86_64.cc @@ -214,6 +214,12 @@ bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { Report("Missing rdtscp support.\n"); return false; } + // Also check whether we can determine the CPU frequency, since if we cannot, + // we should use the emulated TSC instead. + if (!getTSCFrequency()) { + Report("Unable to determine CPU frequency.\n"); + return false; + } return true; } |