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Perf (Linux)
perf (sometimes called perf_events or perf tools, originally Performance Counters for Linux, PCL) is a performance analyzing tool in Linux, available from Linux kernel version 2.6.31 in 2009. Userspace controlling utility, named perf, is accessed from the command line and provides a number of subcommands; it is capable of statistical profiling of the entire system (both kernel and userland code). It supports hardware performance counters, tracepoints, software performance counters (e.g. hrtimer), and dynamic probes (for example, kprobes or uprobes). In 2012, two IBM engineers recognized perf (along with OProfile) as one of the two most commonly used performance counter profiling tools on Linux. Implementation The interface between the perf utility and the kernel consists of only one syscall and is done via a file descriptor and a mapped memory region.Roberto A. Vitillo (LBNL)PERFORMANCE TOOLS DEVELOPMENTS 16 June 2011, presentation from "Future computing in particle phys ...
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Linux Kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU operating system, which was written to be a free (libre) replacement for Unix. Linux is provided under the GNU General Public License version 2 only, but it contains files under other compatible licenses. Since the late 1990s, it has been included as part of a large number of operating system distributions, many of which are commonly also called Linux. Linux is deployed on a wide variety of computing systems, such as embedded devices, mobile devices (including its use in the Android operating system), personal computers, servers, mainframes, and supercomputers. It can be tailored for specific architectures and for several usage scenarios using a family of simple commands (that is, without the need of manually editing its source code ...
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PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., Apple–IBM–Motorola alliance, known as AIM alliance, AIM. PowerPC, as an evolving instruction set, has been named Power ISA since 2006, while the old name lives on as a trademark for some implementations of Power Architecture–based processors. PowerPC was the cornerstone of AIM's PReP and Common Hardware Reference Platform (CHRP) initiatives in the 1990s. Originally intended for personal computers, the architecture is well known for being used by Apple's Power Macintosh, PowerBook, iMac, iBook, eMac, Mac Mini, and Xserve lines from 1994 until 2005, when Mac transition to Intel processors, Apple migrated to Intel's x86. It has since become a niche in personal computers, but remains popular for embedded system, embedded and high-performanc ...
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Red Hat Enterprise Linux
Red Hat Enterprise Linux (RHEL) is a commercial open-source Linux distribution developed by Red Hat for the commercial market. Red Hat Enterprise Linux is released in server versions for x86-64, Power ISA, ARM64, and IBM Z and a desktop version for x86-64. Fedora Linux serves as its upstream source. All of Red Hat's official support and training, together with the Red Hat Certification Program, focuses on the Red Hat Enterprise Linux platform. The first version of Red Hat Enterprise Linux to bear the name originally came onto the market as "Red Hat Linux Advanced Server". In 2003, Red Hat rebranded Red Hat Linux Advanced Server to "Red Hat Enterprise Linux AS" and added two more variants, Red Hat Enterprise Linux ES and Red Hat Enterprise Linux WS. Red Hat uses strict trademark rules to restrict free re-distribution of their officially supported versions of Red Hat Enterprise Linux but still freely provides its source code. Third-party derivatives can be built and redistribut ...
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Linux Kernel Mainline
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU operating system, which was written to be a free (libre) replacement for Unix. Linux is provided under the GNU General Public License version 2 only, but it contains files under other compatible licenses. Since the late 1990s, it has been included as part of a large number of operating system distributions, many of which are commonly also called Linux. Linux is deployed on a wide variety of computing systems, such as embedded devices, mobile devices (including its use in the Android operating system), personal computers, servers, mainframes, and supercomputers. It can be tailored for specific architectures and for several usage scenarios using a family of simple commands (that is, without the need of manually editing its source code be ...
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Pentium 4
Pentium 4 is a series of single-core CPUs for desktops, laptops and entry-level servers manufactured by Intel. The processors were shipped from November 20, 2000 until August 8, 2008. The production of Netburst processors was active from 2000 until May 21, 2010. All Pentium 4 CPUs are based on the NetBurst microarchitecture. The Pentium 4 '' Willamette'' (180 nm) introduced SSE2, while the '' Prescott'' (90 nm) introduced SSE3. Later versions introduced Hyper-Threading Technology (HTT). The first Pentium 4-branded processor to implement 64-bit was the ''Prescott'' (90 nm) (February 2004), but this feature was not enabled. Intel subsequently began selling 64-bit Pentium 4s using the ''"E0" revision'' of the Prescotts, being sold on the OEM market as the Pentium 4, model F. The E0 revision also adds eXecute Disable (XD) (Intel's name for the NX bit) to Intel 64. Intel's official launch of Intel 64 (under the name EM64T at that time) in mainstream deskt ...
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Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 series of instruction sets, the instruction sets found in most personal computers (PCs). Incorporated in Delaware, Intel ranked No. 45 in the 2020 ''Fortune'' 500 list of the largest United States corporations by total revenue for nearly a decade, from 2007 to 2016 fiscal years. Intel supplies microprocessors for computer system manufacturers such as Acer, Lenovo, HP, and Dell. Intel also manufactures motherboard chipsets, network interface controllers and integrated circuits, flash memory, graphics chips, embedded processors and other devices related to communications and computing. Intel (''int''egrated and ''el''ectronics) was founded on July 18, 1968, by semiconductor pioneers Gordon Moore (of Moore's law) and Robert Noyce ( ...
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Branch Trace
A branch, sometimes called a ramus in botany, is a woody structural member connected to the central trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term ''twig'' usually refers to a terminus, while ''bough'' refers only to branches coming directly from the trunk. Due to a broad range of species of trees, branches and twigs can be found in many different shapes and sizes. While branches can be nearly horizontal, vertical, or diagonal, the majority of trees have upwardly diagonal branches. A number of mathematical properties are associated with tree branchings; they are natural examples of fractal patterns in nature, and, as observed by Leonardo da Vinci, their cross-sectional areas closely follow the da Vinci branching rule. Terminology Because of the enormous quantity of branches in the world, there are numerous names in English alone for them. In general however, unspecific words for a branch (such as ...
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SuperH
SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems. At the time of introduction, SuperH was notable for having fixed-length 16-bit instructions in spite of its 32-bit architecture. This was a novel approach; at the time, RISC processors always used an instruction size that was the same as the internal data width, typically 32 bits. Using smaller instructions had consequences: the register file was smaller and instructions were generally two-operand format. But for the market the SuperH was aimed at, this was a small price to pay for the improved memory and processor cache efficiency. Later versions of the design, starting with SH-5, included both 16- and 32-bit instructions, with the 16-bit versions mapping onto the 32-bit version inside the CPU. This allowed the machine code to continue using ...
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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 (CISC) and to be a highly competitive RISC processor for Unix workstations and similar markets. Alpha is implemented in a series of microprocessors originally developed and fabricated by DEC. These microprocessors are most prominently used in a variety of DEC workstations and servers, which eventually formed the basis for almost all of their mid-to-upper-scale lineup. Several third-party vendors also produced Alpha systems, including PC form factor motherboards. Operating systems that support Alpha included OpenVMS (formerly named OpenVMS AXP), Tru64 UNIX (formerly named DEC OSF/1 AXP and Digital UNIX), Windows NT (discontinued after NT 4.0; and prerelease Windows 2000 RC2), Linux ( Debian, SUSE, Gentoo and Red Hat), BSD UNIX ( Ne ...
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Cortex-A9
The ARM Cortex-A9 MPCore is a 32-bit multi-core processor that provides up to 4 cache-coherent cores, each implementing the ARM v7 architecture instruction set. It was introduced in 2007. Features Key features of the Cortex-A9 core are: * out-of-order execution, Out-of-order speculative execution, speculative issue superscalar execution 8-stage instruction pipeline, pipeline giving 2.50 Dhrystone, DMIPS/MHz/core. * ARM NEON, NEON SIMD instruction set extension performing up to 16 operations per instruction (optional). * High performance VFPv3 floating point unit doubling the performance of previous ARM FPUs (optional). * Thumb-2 instruction set encoding reduces the size of programs with little impact on performance. * ARM architecture#Security extensions (TrustZone), TrustZone security extensions. * Jazelle DBX support for Java execution. * Jazelle RCT for JIT compilation. * Program Trace Macrocell and CoreSight Design Kit for non-intrusive tracing of instruction executi ...
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Cortex-A8
The ARM Cortex-A8 is a 32-bit processor core licensed by ARM Holdings implementing the ARMv7-A architecture. Compared to the ARM11, the Cortex-A8 is a dual-issue superscalar design, achieving roughly twice the instructions per cycle. The Cortex-A8 was the first Cortex design to be adopted on a large scale in consumer devices. Features Key features of the Cortex-A8 core are: * Frequency from 600 MHz to 1 GHz and above * Superscalar dual-issue microarchitecture * NEON SIMD instruction set extension * 13-stage integer pipeline and 10-stage NEON pipeline * VFPv3 Floating Point Unit * Thumb-2 instruction set encoding * Jazelle RCT (Also known as ThumbEE instruction set) * Advanced branch prediction unit with >95% accuracy * Integrated level 2 Cache (0–4 MiB) * 2.0 DMIPS/MHz Chips Several system-on-chips (SoC) have implemented the Cortex-A8 core, including: * Allwinner A1X * Apple A4 * Freescale Semiconductor i.MX51 * Rockchip RK2918, RK2906 * Samsung Ex ...
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ARM Architecture
ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of reduced instruction set computer (RISC) instruction set architectures for computer processors, configured for various environments. Arm Ltd. develops the architectures and licenses them to other companies, who design their own products that implement one or more of those architectures, including system on a chip (SoC) and system on module (SOM) designs, that incorporate different components such as memory, interfaces, and radios. It also designs cores that implement these instruction set architectures and licenses these designs to many companies that incorporate those core designs into their own products. There have been several generations of the ARM design. The original ARM1 used a 32-bit internal structure but had a 26-bit address space that limited it to 64 MB of main memory. This limitation was removed in the ARMv3 series, which ...
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