From: Daniel Pieczko <dpiec...@solarflare.com> When the interrupt servicing a channel is on a NUMA node that is not local to the device, performance is improved by allocating rx pages on the node local to the interrupt (remote to the device)
The performance-optimal case, where interrupts and applications are pinned to CPUs on the same node as the device, is not altered by this change. This change gave a 1% improvement in transaction rate using Nginx with all interrupts and Nginx threads on the node remote to the device. It also gave a small reduction in round-trip latency, again with the interrupt and application on a different node to the device. Allocating rx pages based on the channel->irq_node value is only valid for the initial driver-load interrupt affinities; if an interrupt is moved later, the wrong node may be used for the allocation. Signed-off-by: Bert Kenward <bkenw...@solarflare.com> Signed-off-by: Edward Cree <ec...@solarflare.com> --- drivers/net/ethernet/sfc/efx.c | 38 +++++++++++++++++++++++++++++++++++ drivers/net/ethernet/sfc/net_driver.h | 3 +++ drivers/net/ethernet/sfc/rx.c | 18 ++++++++++++++--- 3 files changed, 56 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index e6fdf35..f7e6ce5 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -449,6 +449,7 @@ efx_alloc_channel(struct efx_nic *efx, int i, struct efx_channel *old_channel) channel->efx = efx; channel->channel = i; channel->type = &efx_default_channel_type; + channel->irq_mem_node = NUMA_NO_NODE; for (j = 0; j < EFX_TXQ_TYPES; j++) { tx_queue = &channel->tx_queue[j]; @@ -1569,6 +1570,38 @@ static int efx_probe_interrupts(struct efx_nic *efx) return 0; } +#ifndef CONFIG_SMP +static void efx_set_interrupt_affinity(struct efx_nic *efx __always_unused) +{ +} + +static void efx_clear_interrupt_affinity(struct efx_nic *efx __always_unused) +{ +} +#else +static void efx_set_interrupt_affinity(struct efx_nic *efx) +{ + struct efx_channel *channel; + unsigned int cpu; + + efx_for_each_channel(channel, efx) { + cpu = cpumask_local_spread(channel->channel, + pcibus_to_node(efx->pci_dev->bus)); + + irq_set_affinity_hint(channel->irq, cpumask_of(cpu)); + channel->irq_mem_node = cpu_to_mem(cpu); + } +} + +static void efx_clear_interrupt_affinity(struct efx_nic *efx) +{ + struct efx_channel *channel; + + efx_for_each_channel(channel, efx) + irq_set_affinity_hint(channel->irq, NULL); +} +#endif /* CONFIG_SMP */ + static int efx_soft_enable_interrupts(struct efx_nic *efx) { struct efx_channel *channel, *end_channel; @@ -3017,6 +3050,7 @@ static void efx_pci_remove_main(struct efx_nic *efx) cancel_work_sync(&efx->reset_work); efx_disable_interrupts(efx); + efx_clear_interrupt_affinity(efx); efx_nic_fini_interrupt(efx); efx_fini_port(efx); efx->type->fini(efx); @@ -3166,6 +3200,9 @@ static int efx_pci_probe_main(struct efx_nic *efx) rc = efx_nic_init_interrupt(efx); if (rc) goto fail5; + + efx_set_interrupt_affinity(efx); + rc = efx_enable_interrupts(efx); if (rc) goto fail6; @@ -3173,6 +3210,7 @@ static int efx_pci_probe_main(struct efx_nic *efx) return 0; fail6: + efx_clear_interrupt_affinity(efx); efx_nic_fini_interrupt(efx); fail5: efx_fini_port(efx); diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 38c4223..28c3673 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -423,6 +423,7 @@ enum efx_sync_events_state { * @sync_events_state: Current state of sync events on this channel * @sync_timestamp_major: Major part of the last ptp sync event * @sync_timestamp_minor: Minor part of the last ptp sync event + * @irq_mem_node: Memory NUMA node of interrupt */ struct efx_channel { struct efx_nic *efx; @@ -468,6 +469,8 @@ struct efx_channel { enum efx_sync_events_state sync_events_state; u32 sync_timestamp_major; u32 sync_timestamp_minor; + + int irq_mem_node; }; #ifdef CONFIG_NET_RX_BUSY_POLL diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index 8956995..eed0c3b 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -163,9 +163,21 @@ static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic) do { page = efx_reuse_page(rx_queue); if (page == NULL) { - page = alloc_pages(__GFP_COLD | __GFP_COMP | - (atomic ? GFP_ATOMIC : GFP_KERNEL), - efx->rx_buffer_order); + /* GFP_ATOMIC may fail because of various reasons, + * and we re-schedule rx_fill from non-atomic + * context in such a case. So, use __GFP_NO_WARN + * in case of atomic. + */ + struct efx_channel *channel; + + channel = efx_rx_queue_channel(rx_queue); + page = alloc_pages_node(channel->irq_mem_node, + __GFP_COMP | + (atomic ? + (GFP_ATOMIC | __GFP_NOWARN) + : GFP_KERNEL), + efx->rx_buffer_order); + if (unlikely(page == NULL)) return -ENOMEM; dma_addr =