CpuSampleLinuxCollector.md

The source code of this class is located at CpuSampleLinuxCollector.hpp.

CpuSampleLinuxCollector is a collector for collecting cpu samples on linux, based on perf_events.

CpuSampleLinuxCollector only support linux.

You may want to read the document of CpuSampleLinuxSymbolResolveInterceptor as well.
In most cases CpuSampleLinuxSymbolResolveInterceptor should be used with CpuSampleLinuxCollector.

Functions in CpuSampleLinuxCollector

setIncludeCallChain

Set whether to include callchain in samples. Exclude callchain in samples will improve performance. Default value is true.

Exclude callchain would break some features like inclusive samples analysis.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setIncludeCallChain(false);

setProcessesUpdateInterval

Set how often to update the list of processes. Default value is 100ms.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setProcessesUpdateInterval(std::chrono::milliseconds(50));

filterProcessBy

Use the specified function to decide which processes to monitor.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->filterProcessBy([](pid_t pid) { return pid == 123; });

filterProcessByName

Use the specified process name to decide which processes to monitor.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->filterProcessByName("a.out");

setSamplePeriod

Set how often to take a sample, the unit is cpu clock. Default value is 100000.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setSamplePeriod(300000);

setMmapPageCount

Set how many pages for the mmap ring buffer, this count is not contains metadata page, and should be power of 2. Default value is 8.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setMmapPageCount(16);

setWakeupEvents

Set the number of records required to raise an event. A larger value may improve performance but delay the collection. Default value is 8.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setWakeupEvents(16);

setExcludeUser

Set whether to exclude samples in user space. Default value is false.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setExcludeUser(true);

setExcludeKernel

Set whether to exclude samples in kernel space. Default value is true.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setExcludeKernel(false);

setExcludeHypervisor

Set whether to exclude samples in hypervisor. Default value is true.

Example:

Profiler<CpuSampleModel> profiler;
auto collector = profiler.useCollector<CpuSampleLinuxCollector>();
collector->setExcludeHypervisor(false);