> From: Bruce Richardson [mailto:[email protected]] > Sent: Monday, 15 December 2025 19.21 > > On Mon, Dec 15, 2025 at 05:58:33PM +0000, Bruce Richardson wrote: > > On Mon, Dec 15, 2025 at 06:54:50PM +0100, Morten Brørup wrote: > > > > From: Bruce Richardson [mailto:[email protected]] > > > > Sent: Monday, 15 December 2025 18.36 > > > > > > > > The default Rx ring size checks did not account for the fact that > the > > > > port would not work correctly if the Rx ring size was only twice > the > > > > free threshold size or less, so add in a new check for this. This > would > > > > generally only apply in cases where very small rings sizes are > being > > > > used, for example, with default Rx free thresh of 32, only ring > size of > > > > 64 would cause issues. > > > > > > > > Signed-off-by: Bruce Richardson <[email protected]> > > > > --- > > > > > > Does dev_info.rx_desc_lim.nb_min returned by rte_eth_dev_info_get() > need correction too? > > > > > The minimum number of descriptors stays the same, however, if > choosing the > > minimum number of descriptors you may need to reduce the > rx_free_thresh > > value. > > > However, I think you raise a good point. I'll see about adding a > specific > error message in case the user is using the default threshold and > setting > the min ring size.
The applications need some generic code sequence that always works, on all NICs. E.g. if an application uses rte_eth_dev_adjust_nb_rx_tx_desc() to move a requested crazy number of descriptors within bounds, and uses the default values for all other parameters, it should work. Nonetheless, more detailed error messages are always helpful. :-) -Morten
