cyclictest 主要是用于测试系统延时，进而判断系统的实时性

使用版本

rt-tests-2.6.tar.gz
numactl v2.0.16

问题

编译时，需要先编译 numactl ，不然会有以下报错：

arm-linux-gnueabihf-gcc -D VERSION=2.6 -c src/cyclictest/cyclictest.c -Wall -Wno-nonnull -Wextra -O2 -g -D_GNU_SOURCE -Isrc/include   -o bld/cyclictest.o
In file included from src/cyclictest/cyclictest.c:33:
src/cyclictest/rt_numa.h:18:10: fatal error: numa.h: 没有那个文件或目录
 #include <numa.h>
          ^~~~~~~~
compilation terminated.
Makefile:106: recipe for target 'bld/cyclictest.o' failed
make: *** [bld/cyclictest.o] Error 1

编译 numactl

文件下载 https://github.com/numactl/numactl/tree/v2.0.16

编译命令：

./autogen.sh
./configure CC=arm-linux-gnueabihf-gcc --host=arm  prefix=~/git/numactl-2.0.16/build
make install

这是主要用到编译生成的 lib 及 include 里的文件

编译 cyclictest

下载文件 ：

https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git/

打开 Makefile 文件：

在 RTTESTLIB 后面加上 -L/home/XXX/git/numactl-2.0.16/build/lib
在 CPPFLAGS 后面加上 -I/home/XXX/git/numactl-2.0.16/build/include

RTTESTLIB = -lrttest -L$(OBJDIR) -L/home/XXX/git/numactl-2.0.16/build/lib
CPPFLAGS += -D_GNU_SOURCE -Isrc/include  -I/home/XXX/git/numactl-2.0.16/build/include

然后使用编译命令

make CROSS_COMPILE=arm-linux-gnueabihf- LDFLAGS=-static

即可在目录中看到 cyclictest

使用

cyclictest V 2.60
Usage:
cyclictest <options>

-a [CPUSET] --affinity     Run thread #N on processor #N, if possible, or if CPUSET
                           given, pin threads to that set of processors in round-
                           robin order.  E.g. -a 2 pins all threads to CPU 2,
                           but -a 3-5,0 -t 5 will run the first and fifth
                           threads on CPU (0),thread #2 on CPU 3, thread #3
                           on CPU 4, and thread #5 on CPU 5.
-A USEC  --aligned=USEC    align thread wakeups to a specific offset
-b USEC  --breaktrace=USEC send break trace command when latency > USEC
-c CLOCK --clock=CLOCK     select clock
                           0 = CLOCK_MONOTONIC (default)
                           1 = CLOCK_REALTIME
         --default-system  Don't attempt to tune the system from cyclictest.
                           Power management is not suppressed.
                           This might give poorer results, but will allow you
                           to discover if you need to tune the system
-d DIST  --distance=DIST   distance of thread intervals in us, default=500
-D       --duration=TIME   specify a length for the test run.
                           Append 'm', 'h', or 'd' to specify minutes, hours or days.
-F       --fifo=<path>     create a named pipe at path and write stats to it
-h       --histogram=US    dump a latency histogram to stdout after the run
                           US is the max latency time to be tracked in microseconds
                           This option runs all threads at the same priority.
-H       --histofall=US    same as -h except with an additional summary column
         --histfile=<path> dump the latency histogram to <path> instead of stdout
-i INTV  --interval=INTV   base interval of thread in us default=1000
         --json=FILENAME   write final results into FILENAME, JSON formatted
         --laptop          Save battery when running cyclictest
                           This will give you poorer realtime results
                           but will not drain your battery so quickly
         --latency=PM_QOS  power management latency target value
                           This value is written to /dev/cpu_dma_latency
                           and affects c-states. The default is 0
-l LOOPS --loops=LOOPS     number of loops: default=0(endless)
         --mainaffinity=CPUSET
                           Run the main thread on CPU #N. This only affects
                           the main thread and not the measurement threads
-m       --mlockall        lock current and future memory allocations
-M       --refresh_on_max  delay updating the screen until a new max
                           latency is hit. Useful for low bandwidth.
-N       --nsecs           print results in ns instead of us (default us)
-o RED   --oscope=RED      oscilloscope mode, reduce verbose output by RED
-p PRIO  --priority=PRIO   priority of highest prio thread
         --policy=NAME     policy of measurement thread, where NAME may be one
                           of: other, normal, batch, idle, fifo or rr.
         --priospread      spread priority levels starting at specified value
-q       --quiet           print a summary only on exit
-r       --relative        use relative timer instead of absolute
-R       --resolution      check clock resolution, calling clock_gettime() many
                           times.  List of clock_gettime() values will be
                           reported with -X
         --secaligned [USEC] align thread wakeups to the next full second
                           and apply the optional offset
-s       --system          use sys_nanosleep and sys_setitimer
-S       --smp             Standard SMP testing: options -a -t and same priority
                           of all threads
        --spike=<trigger>  record all spikes > trigger
        --spike-nodes=[num of nodes]
                           These are the maximum number of spikes we can record.
                           The default is 1024 if not specified
-t       --threads         one thread per available processor
-t [NUM] --threads=NUM     number of threads:
                           without NUM, threads = max_cpus
                           without -t default = 1
         --tracemark       write a trace mark when -b latency is exceeded
-u       --unbuffered      force unbuffered output for live processing
-v       --verbose         output values on stdout for statistics
                           format: n:c:v n=tasknum c=count v=value in us
         --dbg_cyclictest  print info useful for debugging cyclictest
-x       --posix_timers    use POSIX timers instead of clock_nanosleep.

使用命令

./cyclictest  -S -p 95  -D 1m -m -i 1000 -d 0

-S 为每个核一个线程，-D 执行一分钟

---

./cyclictest   -p 95  -D 1m -m -i 1000 -d 0 -t 10 -a 5-7

-t 设置 10 个线程， -a 设置在核 5-7上跑

T:   线程序号
P:   线程优先级
C:   线程执行次数
I:   线程运行间隔(us)
Min: 最小延时(us)
Act: 最近一次的延时(us)
Avg：平均延时(us)
Max：最大延时(us)

参考

https://github.com/CJTSAJ/jailhouse-learning/blob/master/%E4%BA%A4%E5%8F%89%E7%BC%96%E8%AF%91cyclictest.md
https://zhuanlan.zhihu.com/p/336381111