Messages in this thread |  | | From | Andy Shevchenko <> | Date | Wed, 6 Jul 2022 14:42:51 +0200 | Subject | Re: [PATCH v2 5/5] iio: pressure: bmp280: Adds more tunable config parameters for BMP380 |
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On Wed, Jul 6, 2022 at 12:51 AM Angel Iglesias <ang.iglesiasg@gmail.com> wrote: > On Mon, 2022-07-04 at 22:08 +0200, Andy Shevchenko wrote: > > On Mon, Jul 4, 2022 at 2:41 AM Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
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> > > + if (unlikely(!data->chip_info->sampling_freq_avail)) { > > > > Why unlikely() ? How does this improve code generation / performance? > > As Jonathan Cameron sugested on a previous version of the patch, even thought > this code should be safe (as if we are checking sampling frequency is because > the sensor is a BMP380 and has that property), it would be better to have a > sanity check just to be sure the property is really available. I used unlikely > macro to take into account that the property would be almost always initialized. > > Now that you mention, probably this code won't be called too often to make the > "unlikely" branching hint make a meaningful performance difference > > > > + if (unlikely(!data->chip_info->iir_filter_coeffs_avail)) { > > > > Ditto.
Is this really a performance-critical path? How did you check that unlikely() makes sense? More evidence, please!
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> > Why do you need to copy'n'paste dozens of the very same comment? > > Wouldn't it be enough to explain it somewhere at the top of the file > > or in the respective documentation (if it exists)?
No answer?
-- With Best Regards, Andy Shevchenko
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