有一些问题我下面提了一下 总的来说，这个小工具有点粗糙，建议好好改一下。最好是能动态显示各CPU的负载，哪怕是固定间隔也是好的。
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Xie Xiuqi Email: xiexiuqi@huawei.commailto:xiexiuqi@huawei.com 发件人：Hongyu Li 543306408@qq.com 收件人：kernel kernel@openeuler.org 抄 送：Xiexiuqi xiexiuqi@huawei.com;chengjian (D) cj.chengjian@huawei.com;Zhengzengkai zhengzengkai@huawei.com 时 间：2021-09-30 20:56:47 主 题：[PATCH openEuler-21.09 2/2] tools: add a tool to calculate the idle rate
openEuler inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4CIJQ CVE: NA
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This tool can help calculate the CPU idle rate in higher precision.
Signed-off-by: Hongyu Li <543306408@qq.commailto:543306408@qq.com> --- tools/accounting/Makefile | 2 +- tools/accounting/idle_cal.c | 91 +++++++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+), 1 deletion(-) create mode 100644 tools/accounting/idle_cal.c
diff --git a/tools/accounting/Makefile b/tools/accounting/Makefile index 03687f19cbb1..d14151e28173 100644 --- a/tools/accounting/Makefile +++ b/tools/accounting/Makefile @@ -2,7 +2,7 @@ CC := $(CROSS_COMPILE)gcc CFLAGS := -I../../usr/include
-PROGS := getdelays +PROGS := getdelays idle_cal
all: $(PROGS)
diff --git a/tools/accounting/idle_cal.c b/tools/accounting/idle_cal.c new file mode 100644 index 000000000000..397b0fc1c69c --- /dev/null +++ b/tools/accounting/idle_cal.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * idle_cal.c + * + * Copyright (C) 2007
为啥是2007 ？
+ * + * cpu idle time accouting + */ + + +#include <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <string.h> +#include <unistd.h> +#include <time.h> +#include <limits.h> +#include <sys/time.h> + +#define CPUS 4
为啥定义成4？系统CPU个数不能这么假设。
+#define BUFFSIZE 4096 +#define HZ 100 +#define FILE_NAME "/proc/stat2" + +struct cpu_info { + char name[BUFFSIZE]; + long long value[1]; +}; + +int main(void) +{ + char buf[BUFFSIZE]; + struct cpu_info cpus[CPUS+1]; + struct cpu_info cpus_2[CPUS+1]; + long long sub; + double value; + + FILE *fp = fopen(FILE_NAME, "r"); + int i = 0; + struct timeval start, end; + + + while (i < CPUS+1) { + int n = fscanf(fp, "%s %lld\n", cpus[i].name, &cpus[i].value[0]); + + if (n < 0) { + printf("wrong"); + return -1; + } + i += 1; + } + + for (int i = 0; i < CPUS+1; i++) + printf("%s %lld\n", cpus[i].name, cpus[i].value[0]);
每次把所有CPU的值打出来，太啰嗦，对使用者没什么意义。下边那个也是。执行一下看一下输出效果就知道了，干扰输出太多 会影响易用性。
+ gettimeofday(&start, NULL); + fflush(fp); + fclose(fp); + i = 0; + + sleep(2); + + FILE *fp_2 = fopen(FILE_NAME, "r"); + + while (i < CPUS+1) { + int n = fscanf(fp_2, "%s %lld\n", cpus_2[i].name, &cpus_2[i].value[0]); + + if (n < 0) { + printf("wrong"); + return -1; + } + i += 1; + } + + for (int i = 0; i < CPUS+1; i++) + printf("%s %lld\n", cpus_2[i].name, cpus_2[i].value[0]); + gettimeofday(&end, NULL); + fclose(fp_2); + + sub = end.tv_sec-start.tv_sec; + value = sub*1000000.0+end.tv_usec-start.tv_usec; + + printf("CPU idle rate %f\n", 1000000/HZ*(cpus_2[0].value[0]-cpus[0].value[0])/value); + + for (int i = 1; i < CPUS+1; i++) { + printf("CPU%d idle rate %f\n", i-1, 1000000/HZ
目的是算系统负载，即 CPU占用率，idle rate 是中间过程，没必要把这个指标作为最后结果输出。
+ *(cpus_2[i].value[0]-cpus[i].value[0])/value); + } + + return 0; +} + -- 2.17.1