On 06/11/2024 13:49, Yafang Shao wrote: > On Wed, Nov 6, 2024 at 5:56 PM Tariq Toukan <ttoukan.linux@xxxxxxxxx> wrote: >> >> >> >> On 06/11/2024 8:40, Yafang Shao wrote: >>> We observed a high number of rx_discards_phy events on some servers when >>> running `ethtool -S`. However, this important counter is not currently >>> reflected in the /proc/net/dev statistics file, making it challenging to >>> monitor effectively. >>> >>> Since rx_missed_errors represents packets dropped due to buffer exhaustion, >>> it makes sense to include rx_discards_phy in this counter to enhance >>> monitoring visibility. This change will help administrators track these >>> events more effectively through standard interfaces. >>> >> >> Hi, >> >> Thanks for your patch. >> >> It's a matter of interpretation... >> The documentation in >> Documentation/ABI/testing/sysfs-class-net-statistics refers to the >> driver for the exact meaning. I think this documentation is outdated, a more recent one is in if_link.h: * @rx_missed_errors: Count of packets missed by the host. * Folded into the "drop" counter in `/proc/net/dev`. * * Counts number of packets dropped by the device due to lack * of buffer space. This usually indicates that the host interface * is slower than the network interface, or host is not keeping up * with the receive packet rate. * * This statistic corresponds to hardware events and is not used * on software devices. >> >> rx_discards_phy counts packet drops due to exhaustion of the physical >> port memory (not in the host), this happen way before steering the >> packet to any receive queue. >> Today, rx_missed_errors counts SW/host memory buffer exhaustion of the >> receive queues. >> I don't think that rx_missed_errors should mix both. > > Thanks for your detailed explanation. > >> >> Maybe some other counter can be used for rx_discards_phy, like >> rx_fifo_errors? > > It appears that rx_fifo_errors is a more appropriate counter for this purpose. > I will submit a v2. Thanks for your suggestion. Probably not a good idea: * This statistics was used interchangeably with @rx_over_errors. * Not recommended for use in drivers for high speed interfaces.
