Tracer

• Support for x86-32, x86-64, PowerPC 32/64, ARMv7 OMAP3, MIPS, sh, sparc64, s390.
• Other Linux architectures supported with limited timestamp precision.
• Static tracing (highly optimized).
• Dynamic tracing support using kprobes.
• Binary trace format highly optimized for compactness.
• Self describing trace format.
• Efficient probes with no trap and no system call.
• Almost zero performance impact with instrumentation points disabled (kernel: uses code modification, userspace: uses fast boolean evaluation).
• Active instrumentation points have low performance impact (a fast C language function call).
• Kernel tracer scalable to high core numbers (uses RCU mechanism, per-cpu buffers, non-blocking atomic operations).
• Support C/C++ and any language that can call C code.
• Reentrant: kernel tracer NMI safe, userspace tracer thread and signal safe.
• Zero copy from event generation to disk write.
• Generate events with arbitrary number of arguments (variable event sizes).
• Support for conditional tracing through custom probes.
• Timestamp precision typically ~1ns (cycle counter).
• Accurate event ordering, even across cores/cpus (except if hardware makes it impossible).
• Supports simultaneous recording of multiple traces.
• Support for arbitrary architecture endianness.
• Tracing modes: write-to-disk, flight recorder, stream to remote disk (under development), live monitoring (local or remote) (under development).
• Traces composed of several channels that have distinct buffers with their own size.
• Flight recorder mode activation is per-channel.

Trace Analysis

• Analysis of extremely large traces (>100GB) with LTTV.
• New Eclipse-based analyzer program currently under development (http://www.eclipse.org/linuxtools/projectPages/lttng/).
• Analysis views: resource view, per thread execution state (control flow view), event rate histogram, detailed event list, filtering, view synchronization, IRQ latency.

Features in progress

• Highly efficient user space tracing
• Online monitoring and trace streaming
• Trace correlation
• Multi-level, multi-core distributed trace synchronization