Re: Query about timer wheel API

[Hillf Danton <hdanton@sina.com>]

On Tue, 24 Dec 2024 01:20:48 +1100 imran.f.khan@oracle.com
> 
> static int param_set_queue_work_on_cpu(const char *val, const struct kernel_param *kp)
> {
> 	int cpu, this_cpu, i;
> 	struct delayed_work *dwork = NULL;
> 
> 	if (!mutex_trylock(&mutex))
> 		return -EBUSY;
> 
> 	cpu = simple_strtoul(val, NULL, 0);
> 	/*if (!cpu_present(cpu)) 
> 		return -EINVAL;*/
> 
> 	for (i = 0; i < NUM_WORK_ITEMS; i++) {
> 		dwork = kzalloc(sizeof(struct delayed_work), GFP_KERNEL);
> 		if(dwork) {
> 			this_cpu = get_cpu();

See if checking cpu works for you.

			if (cpu >= nr_cpu_ids || !cpu_online(cpu)) {
 				put_cpu();
				pr_err("%s cpu%d invalid\n", __func__, cpu);
				break;
			}

> 			INIT_DELAYED_WORK(dwork, delayed_work_func);
> 			queue_delayed_work_on(cpu, system_wq, dwork, msecs_to_jiffies(10000));
> 			pr_err("Submitted dwork 0x%px on %s cpu#%d \n", dwork, cpu_online(cpu)?"online":"offline", cpu);
> 			put_cpu();
> 		}
> 
> 	}
> 	mutex_unlock(&mutex);
> 	return 0;
> }