From: Gatis Peisenieks <ga...@mikrotik.com> Date: Tue, 06 Apr 2021 17:49:32 +0300
> Tx queue cleanup happens in interrupt handler on same core as rx queue > processing. Both can take considerable amount of processing in high > packet-per-second scenarios. > > Sending big amounts of packets can stall the rx processing which is > unfair > and also can lead to out-of-memory condition since __dev_kfree_skb_irq > queues the skbs for later kfree in softirq which is not allowed to > happen > with heavy load in interrupt handler. > > This puts tx cleanup in its own napi and enables threaded napi to > allow > the rx/tx queue processing to happen on different cores. Also as the > first > in-driver user of dev_set_threaded API, need to add EXPORT_SYMBOL for > it. > > The ability to sustain equal amounts of tx/rx traffic increased: > from 280Kpps to 1130Kpps on Threadripper 3960X with upcoming > Mikrotik 10/25G NIC, > from 520Kpps to 850Kpps on Intel i3-3320 with Mikrotik RB44Ge adapter. > > Signed-off-by: Gatis Peisenieks <ga...@mikrotik.com> > --- > changes since v3: > - made scripts/checkpatch.pl happy (commit message line wrap + > missing comment on spinlock) > - moved the new intr_mask_lock to be besides the intr_mask it > protects so they are more likely to be on same cacheline > changes since v2: > - addressed comments from Eric Dumazet > - added EXPORT_SYMBOL for dev_set_threaded > > Sorry for reposting, noticed that scripts/checkpatch.pl was not happy. This does not apply to 'net', did you mean 'net-next'? If so, please indicate this clearly in the Subject line as per convention. Thank you.
