Re: [PATCH V6 02/16] rv: Add runtime reactors interface

[Daniel Bristot de Oliveira]

On 7/20/22 18:41, Steven Rostedt wrote:
> On Tue, 19 Jul 2022 19:27:07 +0200
> Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote:
> 
>> +/*
>> + * reacting_on interface.
>> + */
>> +static ssize_t reacting_on_read_data(struct file *filp,
>> +				     char __user *user_buf,
>> +				     size_t count, loff_t *ppos)
>> +{
>> +	char *buff;
>> +
>> +	mutex_lock(&rv_interface_lock);
>> +	buff = reacting_on ? "1\n" : "0\n";
>> +	mutex_unlock(&rv_interface_lock);
> Again, no need for the locks, but perhaps just to keep things sane:
> 
> 	buf = READ_ONCE(reacting_on) ? "1\n" : "0\n";

So, for all files that only read/write a single variable, use READ_ONCE/WRITE_ONCE without
locks? (and in all usage of that variable too).

-- Daniel
> -- Steve
>