Re: [PATCH v7 06/16] lockdep: Detect and handle hist_lock ring buffer overwrite

[Byungchul Park]

On Thu, Jul 13, 2017 at 10:14:42AM +0200, Peter Zijlstra wrote:
> +static void __crossrelease_end(unsigned int *stamp)
> +{

[snip]

> +
> +	/*
> +	 * If we rewind past the tail; all of history is lost.
> +	 */
> +	if ((current->xhlock_idx_max - *stamp) < MAX_XHLOCKS_NR)
> +		return;
> +
> +	/*
> +	 * Invalidate the entire history..
> +	 */
> +	for (i = 0; i < MAX_XHLOCKS_NR; i++)
> +		invalidate_xhlock(&xhlock(i));
> +
> +	current->xhlock_idx = 0;
> +	current->xhlock_idx_hard = 0;
> +	current->xhlock_idx_soft = 0;
> +	current->xhlock_idx_hist = 0;
> +	current->xhlock_idx_max = 0;

I don't understand why you introduced this code, yet. Do we need this?

The other of your suggestion looks very good though..

> +}