On 2026-02-05 08:54:34 [+0100], Kurt Kanzenbach wrote: > Retrieve Tx timestamp directly from interrupt handler for i210. > > The current implementation uses schedule_work() which is executed by the > system work queue to retrieve Tx timestamps. This increases latency and can > lead to timeouts in case of heavy system load. i210 is often used in > industrial systems, where timestamp timeouts can be fatal. > > Therefore, fetch the timestamp directly from the interrupt handler. > > The work queue code stays for all other NICs supported by igb. > > Tested on Intel i210 and i350. > > Signed-off-by: Kurt Kanzenbach <[email protected]>
Reviewed-by: Sebastian Andrzej Siewior <[email protected]> IMHO this is a compromise with Miroslav where he observed less PTP timestamps on the i350. While testing I did not get near Miroslav's difference but there was a small change. I don't understand *why* because the current workqueue usage reads the timestamp on the same CPU on which the interrupt occurred. Doing it directly just avoids the context switch. This feels beneficial. Sebastian
