内核线程绑定CPU

内核线程绑定到CPU上执行测试代码：

From 12f206e044f467919180aa26148eaacd82964ece Mon Sep 17 00:00:00 2001From: Chen Jun <[e-mail]>Date: Thu, 7 Dec 2017 08:24:52 -0800Subject: [PATCH] bind kthread on cpu Test--- arch/arm64/Kconfig |  2 +- fs/proc/uptime.c   | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 1 deletion(-)diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfigindex 6df1e6e..ecbb44b 100644--- a/arch/arm64/Kconfig+++ b/arch/arm64/Kconfig@@ -580,7 +580,7 @@ config NR_CPUS    int "Maximum number of CPUs (2-4096)"    range 2 4096    # These have to remain sorted largest to smallest-   default "64"+   default "8" config HOTPLUG_CPU    bool "Support for hot-pluggable CPUs"diff --git a/fs/proc/uptime.c b/fs/proc/uptime.cindex 33de567..c237260 100644--- a/fs/proc/uptime.c+++ b/fs/proc/uptime.c@@ -6,6 +6,54 @@ #include <linux/time.h> #include <linux/kernel_stat.h> #include <linux/cputime.h>+#include <linux/kthread.h>+#include <linux/delay.h>++static DECLARE_COMPLETION(thread_done);+static atomic_long_t count = ATOMIC64_INIT(0);++static int thread_func(void *arg)+{+   int cpu;+   long long val;++   cpu = *(int *)arg;+   pr_err("%s start on cpu%d\n", __func__, cpu);++   msleep(10000);+   pr_err("%s end on cpu%d\n", __func__, cpu);++   if ((val = atomic64_inc_return(&count)) >= NR_CPUS) {+       pr_err("%s %d end atomic %lld\n", __func__, cpu, val);+       complete(&thread_done);+   }++   return 0;+}++static void self_test(void)+{+   int cpu, ret;+   struct task_struct *kthread[8] = {0};++   init_completion(&thread_done);+   memset(&count, 0, sizeof(count));++   for_each_online_cpu(cpu) {+       kthread[cpu] = kthread_create_on_cpu(thread_func, &cpu, cpu, "cjthread/%d");+       if (IS_ERR(kthread[cpu])) {+           pr_err("fail to kthread_create_on_cpu\n");+           return ;+       }+   }++   for_each_online_cpu(cpu) {+       ret = wake_up_process(kthread[cpu]);+       pr_err("wake_up_process %d ret %d\n", cpu, ret);+   }+   wait_for_completion(&thread_done);+   pr_err("%s %d completed\n", __func__, __LINE__);+} static int uptime_proc_show(struct seq_file *m, void *v) {@@ -16,6 +64,7 @@ static int uptime_proc_show(struct seq_file *m, void *v)    u32 rem;    int i;+   self_test();    idletime = 0;    for_each_possible_cpu(i)        idletime += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE];-- 2.7.4