computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...

, OProfile is a system-wide

statistical Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...

profiling tool for

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

. John Levon wrote it in 2001 for

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

version 2.4 after his M.Sc. project; it consists of a

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

module, a user-space

daemon A demon is a malevolent supernatural being, evil spirit or fiend in religion, occultism, literature, fiction, mythology and folklore. Demon, daemon or dæmon may also refer to: Entertainment Fictional entities * Daemon (G.I. Joe), a character ...

and several user-space tools.

Details

OProfile can profile an entire system or its parts, from interrupt routines or drivers, to user-space processes. It has low overhead. The most widely supported kernel mode of uses a system timer (See: Gathering profiling events). However, this mode is unable to measure kernel functions where interrupts are disabled. Newer CPU models support a

hardware performance counter In computers, hardware performance counters (HPCs), or hardware counters are a set of special-purpose registers built into modern microprocessors to store the counts of hardware-related activities. Advanced users often rely on those counters to cond ...

mode which uses hardware logic to record events without any active code needed. In Linux 2.2/2.4 only 32-bit

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...

and

IA64 IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the discontinued Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented b ...

are supported; in Linux 2.6 there is wider support: x86 (32 and 64 bit),

DEC Alpha Alpha (original name Alpha AXP) is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers ( ...

, MIPS,

ARM In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between ...

, sparc64,

ppc64 ppc64 is an identifier commonly used within the Linux, GNU Compiler Collection (GCC) and LLVM free software communities to refer to the target architecture for applications optimized for 64-bit big-endian PowerPC and Power ISA processors. ppc64 ...

AVR32 AVR32 is a 32-bit RISC microcontroller architecture produced by Atmel. The microcontroller architecture was designed by a handful of people educated at the Norwegian University of Science and Technology, including lead designer Øyvind Strøm ...

Call graph A call graph (also known as a call multigraph) is a control-flow graph, which represents calling relationships between subroutines in a computer program. Each node represents a procedure and each edge ''(f, g)'' indicates that procedure ''f'' c ...

s are supported only on x86 and ARM. In 2012 two IBM engineers recognized OProfile as one of the two most commonly used performance counter monitor profiling tools on Linux, alongside perf tool. In 2021, OProfile is set to be removed from version 5.12 of the Linux kernel, with the user-space tools continuing to work by using the kernel's perf system.

User-space tools

* is used to start and stop the daemon, which collects profiling data. This data is periodically saved to the directory. * shows basic profiling data. can produce annotated

sources Source may refer to: Research * Historical document * Historical source * Source (intelligence) or sub source, typically a confidential provider of non open-source intelligence * Source (journalism), a person, publication, publishing institute ...

or assembly. * converts from oprofile data into

gprof Gprof is a performance analysis tool for Unix applications. It used a hybrid of instrumentation and samplingSusan L. Graham, Peter B. Kessler, and Marshall K. Mckusick''gprof: a Call Graph Execution Profiler''// Proceedings of the SIGPLAN '82 Sy ...

-compatible format. Example:

References

External links

* {{Official website, http://oprofile.sourceforge.net/news/ * W. Cohen
Tuning programs with OProfile
// Wide Open Magazine, 2004, pages 53–62 * Prasanna Panchamukhi

// IBM DeveloperWorks, Technical Library, 16 Oct 2003 * Justin Thiel

(2006) "2.2.2 Overview of Oprofile" Linux kernel features Profilers

Details

User-space tools

See also

References

External links