Re: [RFC PATCH v2 05/20] tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU

On 29/07/23 15:34, Steven Rostedt wrote:

On Thu, 20 Jul 2023 17:30:41 +0100 Valentin Schneider vschneid@redhat.com wrote:

...

         /* Move along */
         i++;

• /*
  

•  * Optimisation: if the user-provided mask has a weight of one
  

•  * then we can treat it as a scalar input.
  

•  */
  

• single = cpumask_weight(pred->mask) == 1;
  

• if (single && field->filter_type == FILTER_CPUMASK) {
  

• 	pred->val = cpumask_first(pred->mask);
  

• 	kfree(pred->mask);
  

Don't we need: pred->mask = NULL;

here, or the free_predicate() will cause a double free?

We do, thanks for spotting this.

-- Steve

...

• }