Re: [PATCH v2 09/16] rcu/tree: Maintain separate array for vmalloc ptrs

Matthew Wilcox
2020-06-18T17:35:31Z

On Thu, Jun 18, 2020 at 07:30:49PM +0200, Uladzislau Rezki wrote:
> > I'd suggest:
> >
> > rcu_lock_acquire(&rcu_callback_map);
> > trace_rcu_invoke_kfree_bulk_callback(rcu_state.name,
> > bkvhead[i]->nr_records, bkvhead[i]->records);
> > if (i == 0) {
> > kfree_bulk(bkvhead[i]->nr_records,
> > bkvhead[i]->records);
> > } else {
> > for (j = 0; j < bkvhead[i]->nr_records; j++) {
> > vfree(bkvhead[i]->records[j]);
> > }
> > }
> > rcu_lock_release(&rcu_callback_map);
> >
> There are two different trace functions, one for "bulk" tracing
> messages, and another one is per one call of kfree(), though we use
> to indicate vfree() call.
>
> Probably we can rename it to: trace_rcu_invoke_kvfree_callback();
>
> What do you think?

Works for me!

> > But I'd also suggest a vfree_bulk be added. There are a few things
> > which would be better done in bulk as part of the vfree process
> > (we batch them up already, but i'm sure we could do better).
>
> I was thinking to implement of vfree_bulk() API, but i guess it can
> be done as future work.
>
> Does that sound good?

Yes, definitely a future piece of work.