Messages in this thread Patch in this message | | | Date | Mon, 29 Apr 2024 19:30:34 +0100 | From | Simon Horman <> | Subject | Re: [PATCH net-next v2] net: ti: icssg_prueth: Add SW TX / RX Coalescing based on hrtimers |
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On Mon, Apr 29, 2024 at 12:45:01PM +0530, MD Danish Anwar wrote: > Add SW IRQ coalescing based on hrtimers for RX and TX data path for ICSSG > driver, which can be enabled by ethtool commands: > > - RX coalescing > ethtool -C eth1 rx-usecs 50 > > - TX coalescing can be enabled per TX queue > > - by default enables coalesing for TX0
nit: coalescing
Please consider running patches through ./checkpatch --codespell
> ethtool -C eth1 tx-usecs 50 > - configure TX0 > ethtool -Q eth0 queue_mask 1 --coalesce tx-usecs 100 > - configure TX1 > ethtool -Q eth0 queue_mask 2 --coalesce tx-usecs 100 > - configure TX0 and TX1 > ethtool -Q eth0 queue_mask 3 --coalesce tx-usecs 100 --coalesce > tx-usecs 100 > > Minimum value for both rx-usecs and tx-usecs is 20us. > > Compared to gro_flush_timeout and napi_defer_hard_irqs this patch allows > to enable IRQ coalescing for RX path separately. > > Benchmarking numbers: > =============================================================== > | Method | Tput_TX | CPU_TX | Tput_RX | CPU_RX | > | ============================================================== > | Default Driver 943 Mbps 31% 517 Mbps 38% | > | IRQ Coalescing (Patch) 943 Mbps 28% 518 Mbps 25% | > =============================================================== > > Signed-off-by: MD Danish Anwar <danishanwar@ti.com> > --- > Changes from v1 [1] to v2: > *) Added Benchmarking numbers in the commit message as suggested by > Andrew Lunn <andrew@lunn.ch>. Full logs [2] > *) Addressed comments given by Simon Horman <horms@kernel.org> in v1.
Sorry to be bothersome, but the W=1 problem isn't entirely fixed.
> > [1] https://lore.kernel.org/all/20240424091823.1814136-1-danishanwar@ti.com/ > > [2] https://gist.githubusercontent.com/danish-ti/47855631be9f3635cee994693662a988/raw/94b4eb86b42fe243ab03186a88a314e0cb272fd0/gistfile1.txt
..
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
..
> @@ -190,19 +191,37 @@ int emac_tx_complete_packets(struct prueth_emac *emac, int chn, > return num_tx; > } > > +static enum hrtimer_restart emac_tx_timer_callback(struct hrtimer *timer) > +{ > + struct prueth_tx_chn *tx_chns = > + container_of(timer, struct prueth_tx_chn, tx_hrtimer); > + > + enable_irq(tx_chns->irq); > + return HRTIMER_NORESTART; > +} > + > static int emac_napi_tx_poll(struct napi_struct *napi_tx, int budget) > { > struct prueth_tx_chn *tx_chn = prueth_napi_to_tx_chn(napi_tx); > struct prueth_emac *emac = tx_chn->emac; > + bool tdown = false; > int num_tx_packets; > > - num_tx_packets = emac_tx_complete_packets(emac, tx_chn->id, budget); > + num_tx_packets = emac_tx_complete_packets(emac, tx_chn->id, budget, > + &tdown); > > if (num_tx_packets >= budget) > return budget; > > - if (napi_complete_done(napi_tx, num_tx_packets)) > - enable_irq(tx_chn->irq); > + if (napi_complete_done(napi_tx, num_tx_packets)) { > + if (unlikely(tx_chn->tx_pace_timeout_ns && !tdown)) { > + hrtimer_start(&tx_chn->tx_hrtimer, > + ns_to_ktime(tx_chn->tx_pace_timeout_ns), > + HRTIMER_MODE_REL_PINNED); > + } else { > + enable_irq(tx_chn->irq); > + }
This compiles with gcc-13 and clang-18 W=1 (although the inner {} are unnecessary).
> + } > > return num_tx_packets; > }
..
> @@ -872,7 +894,13 @@ int emac_napi_rx_poll(struct napi_struct *napi_rx, int budget) > } > > if (num_rx < budget && napi_complete_done(napi_rx, num_rx)) > - enable_irq(emac->rx_chns.irq[rx_flow]); > + if (unlikely(emac->rx_pace_timeout_ns)) { > + hrtimer_start(&emac->rx_hrtimer, > + ns_to_ktime(emac->rx_pace_timeout_ns), > + HRTIMER_MODE_REL_PINNED); > + } else { > + enable_irq(emac->rx_chns.irq[rx_flow]); > + }
But this does not; I think outer (but not inner) {} are needed.
FIIIW, I believe this doesn't show-up in the netdev automated testing because this driver isn't built for x86 allmodconfig.
> > return num_rx; > }
..
-- pw-bot: changes-requested
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