On Mon, Nov 28, 2022 at 08:39:24AM +0200, Tariq Toukan wrote: > > > On 11/17/2022 2:23 PM, Valentin Schneider wrote: > > On 15/11/22 10:32, Yury Norov wrote: > > > On Tue, Nov 15, 2022 at 05:24:56PM +0000, Valentin Schneider wrote: > > > > > > > > Is this meant as a replacement for [1]? > > > > > > No. Your series adds an iterator, and in my experience the code that > > > uses iterators of that sort is almost always better and easier to > > > understand than cpumask_nth() or cpumask_next()-like users. > > > > > > My series has the only advantage that it allows keep existing codebase > > > untouched. > > > > > > > Right > > > > > > I like that this is changing an existing interface so that all current > > > > users directly benefit from the change. Now, about half of the users of > > > > cpumask_local_spread() use it in a loop with incremental @i parameter, > > > > which makes the repeated bsearch a bit of a shame, but then I'm tempted to > > > > say the first point makes it worth it. > > > > > > > > [1]: https://lore.kernel.org/all/20221028164959.1367250-1-vschneid@xxxxxxxxxx/ > > > > > > In terms of very common case of sequential invocation of local_spread() > > > for cpus from 0 to nr_cpu_ids, the complexity of my approach is n * log n, > > > and your approach is amortized O(n), which is better. Not a big deal _now_, > > > as you mentioned in the other email. But we never know how things will > > > evolve, right? > > > > > > So, I would take both and maybe in comment to cpumask_local_spread() > > > mention that there's a better alternative for those who call the > > > function for all CPUs incrementally. > > > > > > > Ack, sounds good. > > > > Good. > Is a respin needed, to add the comment mentioned above? If you think it's worth the effort.
