vmstat system in cs cs: The number of context switches per second. 高

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http://lxr.free-electrons.com/source/kernel/trace/Kconfig

config CONTEXT_SWITCH_TRACER
86         bool
87
88 config RING_BUFFER_ALLOW_SWAP
89         bool
90         help
91          Allow the use of ring_buffer_swap_cpu.
92          Adds a very slight overhead to tracing when enabled.
93
94 # All tracer options should select GENERIC_TRACER. For those options that are
95 # enabled by all tracers (context switch and event tracer) they select TRACING.
96 # This allows those options to appear when no other tracer is selected. But the
97 # options do not appear when something else selects it. We need the two options
98 # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
99 # hiding of the automatic options.





pidstat -w  
Linux 2.6.32-279.el6.x86_64 (centostmp-lvm)     2014年04月30日  _x86_64_        (3 CPU)

11时07分06秒       PID   cswch/s nvcswch/s  Command
11时07分06秒         1      1.70      0.00  init
11时07分06秒         2      0.00      0.00  kthreadd
11时07分06秒         3      2.14      0.00  migration/0
11时07分06秒         4      9.16      0.36  ksoftirqd/0





http://en.wikipedia.org/wiki/LTTng





​LMbench的简单介绍？

    ​    首先看英文介绍：LMbench -Tools for Performance Analysis，微观性能分析工具。

     ​   官方地址：http://www.bitmover.com/lmbench/








CONFIG_CONTEXT_SWITCH_TRACER: Trace process context switches
General informations

The Linux kernel configuration item CONFIG_CONTEXT_SWITCH_TRACER has multiple definitions:
found in kernel/trace/Kconfig

The configuration item CONFIG_CONTEXT_SWITCH_TRACER:

    prompt:
    type: bool
    depends on: (none)
    defined in kernel/trace/Kconfig
    found in Linux kernels: 2.6.31–2.6.39, 3.0–3.14, 3.14+HEAD

Help text

(none)
Trace process context switches found in kernel/trace/Kconfig

The configuration item CONFIG_CONTEXT_SWITCH_TRACER:

    prompt: Trace process context switches
    type: bool
    depends on: (none)
    defined in kernel/trace/Kconfig
    found in Linux kernels: 2.6.27–2.6.30

Help text

This tracer gets called from the context switch and records all switching of tasks.
Hardware
LKDDb

Raw data from LKDDb:

    (none)

Sources

This page is automaticly generated with free (libre, open) software lkddb(see lkddb-sources).

The data is retrived from:

    Linux kernel
    Linux Kernel Driver DataBase (LKDDb)