Re: Perf loses events without reporting

[Jiri Olsa <jolsa@redhat.com>]

On Thu, Jul 01, 2021 at 11:00:24AM -0700, Stephen Brennan wrote:

SNIP

> 
> static ssize_t irqsoff_write(struct file *f, const char __user *data, size_t amt, loff_t *off)
> {
> 	char buf[32];
> 	int rv;
> 	unsigned long millis = 0;
> 
> 	if (amt > sizeof(buf) - 1)
> 		return -EFBIG;
> 
> 	if ((rv = copy_from_user(buf, data, amt)) != 0)
> 		return -EFAULT;
> 
> 	buf[amt] = '\0';
> 
> 	if (sscanf(buf, "%lu", &millis) != 1)
> 		return -EINVAL;
> 
> 	/* Threshold it at 5 minutes for safety. */
> 	if (millis > 5 * 60 * 1000)
> 		return -EINVAL;
> 
> 	pr_info("[irqoff] lock for %lu millis\n", millis);
> 	spin_lock_irq(&irqoff_lock);
> 	irqsoff_inirq_delay(millis);
> 	spin_unlock_irq(&irqoff_lock);

yea, I can see that as well.. if I took the spin_lock_irq it works as
expected.. will check

thanks,
jirka