[v3,net-next,3/4] ixgbe: Add support for ndo_ll_poll

Message ID	20130520101622.14133.21998.stgit@ladj378.jer.intel.com
State	Changes Requested, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Eliezer Tamir <eliezer.tamir@linux.intel.com> Subject: [PATCH v3 net-next 3/4] ixgbe: Add support for ndo_ll_poll To: Dave Miller <davem@davemloft.net> Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jesse Brandeburg <jesse.brandeburg@intel.com>, Don Skidmore <donald.c.skidmore@intel.com>, e1000-devel@lists.sourceforge.net, Willem de Bruijn <willemb@google.com>, Andi Kleen <andi@firstfloor.org>, HPA <hpa@zytor.com>, Eliezer Tamir <eliezer@tamir.org.il> Date: Mon, 20 May 2013 13:16:22 +0300 Message-ID: <20130520101622.14133.21998.stgit@ladj378.jer.intel.com> In-Reply-To: <20130520101552.14133.45953.stgit@ladj378.jer.intel.com> References: <20130520101552.14133.45953.stgit@ladj378.jer.intel.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h index ca93238..72be661 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h @@ -356,9 +356,105 @@ struct ixgbe_q_vector { struct rcu_head rcu; /* to avoid race with update stats on free */ char name[IFNAMSIZ + 9]; +#ifdef CONFIG_INET_LL_RX_POLL + unsigned int state; +#define IXGBE_QV_STATE_IDLE 0 +#define IXGBE_QV_STATE_NAPI 1 /* NAPI owns this QV */ +#define IXGBE_QV_STATE_POLL 2 /* poll owns this QV */ +#define IXGBE_QV_LOCKED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL) +#define IXGBE_QV_STATE_NAPI_YIELD 4 /* NAPI yielded this QV */ +#define IXGBE_QV_STATE_POLL_YIELD 8 /* poll yielded this QV */ +#define IXGBE_QV_YIELD (IXGBE_QV_STATE_NAPI_YIELD | IXGBE_QV_STATE_POLL_YIELD) +#define IXGBE_QV_USER_PEND (IXGBE_QV_STATE_POLL | IXGBE_QV_STATE_POLL_YIELD) + spinlock_t lock; +#endif /* CONFIG_INET_LL_RX_POLL */ + /* for dynamic allocation of rings associated with this q_vector */ struct ixgbe_ring ring[0] ____cacheline_internodealigned_in_smp; }; +#ifdef CONFIG_INET_LL_RX_POLL +static inline void ixgbe_qv_init_lock(struct ixgbe_q_vector *q_vector) +{ + + spin_lock_init(&q_vector->lock); + q_vector->state = IXGBE_QV_STATE_IDLE; +} + +/* called from the device poll rutine to get ownership of a q_vector */ +static inline int ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) +{ + int rc = true; + spin_lock(&q_vector->lock); + if (q_vector->state & IXGBE_QV_LOCKED) { + WARN_ON(q_vector->state & IXGBE_QV_STATE_NAPI); + q_vector->state |= IXGBE_QV_STATE_NAPI_YIELD; + rc = false; + } else + /* we don't care if someone yielded */ + q_vector->state = IXGBE_QV_STATE_NAPI; + spin_unlock(&q_vector->lock); + return rc; +} + +/* returns true is someone tried to get the qv while napi had it */ +static inline int ixgbe_qv_unlock_napi(struct ixgbe_q_vector *q_vector) +{ + int rc = false; + spin_lock(&q_vector->lock); + WARN_ON(q_vector->state & (IXGBE_QV_STATE_POLL | + IXGBE_QV_STATE_NAPI_YIELD)); + + if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD) + rc = true; + q_vector->state = IXGBE_QV_STATE_IDLE; + spin_unlock(&q_vector->lock); + return rc; +} + +/* called from ixgbe_low_latency_poll() */ +static inline int ixgbe_qv_lock_poll(struct ixgbe_q_vector *q_vector) +{ + int rc = true; + spin_lock_bh(&q_vector->lock); + if ((q_vector->state & IXGBE_QV_LOCKED)) { + q_vector->state |= IXGBE_QV_STATE_POLL_YIELD; + rc = false; + } else + /* preserve yield marks */ + q_vector->state |= IXGBE_QV_STATE_POLL; + spin_unlock_bh(&q_vector->lock); + return rc; +} + +/* returns true if someone tried to get the qv while it was locked */ +static inline int ixgbe_qv_unlock_poll(struct ixgbe_q_vector *q_vector) +{ + int rc = false; + spin_lock_bh(&q_vector->lock); + WARN_ON(q_vector->state & (IXGBE_QV_STATE_NAPI)); + + if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD) + rc = true; + q_vector->state = IXGBE_QV_STATE_IDLE; + spin_unlock_bh(&q_vector->lock); + return rc; +} + +/* true if a socket is polling, even if it did not get the lock */ +static inline int ixgbe_qv_ll_polling(struct ixgbe_q_vector *q_vector) +{ + WARN_ON(!(q_vector->state & IXGBE_QV_LOCKED)); + return q_vector->state & IXGBE_QV_USER_PEND; +} +#else +#define ixgbe_qv_init_lock(qv) do {} while (0) +#define ixgbe_qv_lock_napi(qv) 1 +#define ixgbe_qv_unlock_napi(qv) 0 +#define ixgbe_qv_lock_poll(qv) 0 +#define ixgbe_qv_unlock_poll(qv) 0 +#define ixgbe_qv_ll_polling(qv) 0 +#endif /* CONFIG_INET_LL_RX_POLL */ + #ifdef CONFIG_IXGBE_HWMON #define IXGBE_HWMON_TYPE_LOC 0 diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index d30fbdd..628b7b1 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -47,6 +47,7 @@ #include <linux/if_bridge.h> #include <linux/prefetch.h> #include <scsi/fc/fc_fcoe.h> +#include <net/ll_poll.h> #include "ixgbe.h" #include "ixgbe_common.h" @@ -144,6 +145,14 @@ static int debug = -1; module_param(debug, int, 0); MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)"); +#ifdef CONFIG_INET_LL_RX_POLL +static int allow_unsafe_removal; +static int unsafe_to_remove; +module_param(allow_unsafe_removal, int, 0); +MODULE_PARM_DESC(allow_unsafe_removal, + "Allow removal of module after low latency receive was used"); +#endif + MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>"); MODULE_DESCRIPTION("Intel(R) 10 Gigabit PCI Express Network Driver"); MODULE_LICENSE("GPL"); @@ -1504,7 +1513,9 @@ static void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector, { struct ixgbe_adapter *adapter = q_vector->adapter; - if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL)) + if (ixgbe_qv_ll_polling(q_vector)) + netif_receive_skb(skb); + else if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL)) napi_gro_receive(&q_vector->napi, skb); else netif_rx(skb); @@ -1892,9 +1903,9 @@ dma_sync: * expensive overhead for IOMMU access this provides a means of avoiding * it by maintaining the mapping of the page to the syste. * - * Returns true if all work is completed without reaching budget + * Returns amount of work completed **/ -static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, +static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, struct ixgbe_ring *rx_ring, const int budget) { @@ -1976,6 +1987,7 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, } #endif /* IXGBE_FCOE */ + skb_mark_ll(skb, &q_vector->napi); ixgbe_rx_skb(q_vector, skb); /* update budget accounting */ @@ -1992,9 +2004,45 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, if (cleaned_count) ixgbe_alloc_rx_buffers(rx_ring, cleaned_count); - return (total_rx_packets < budget); + return total_rx_packets; } +#ifdef CONFIG_INET_LL_RX_POLL +/* must be called with local_bh_disable()d */ +static int ixgbe_low_latency_recv(struct napi_struct *napi) +{ + struct ixgbe_q_vector *q_vector = + container_of(napi, struct ixgbe_q_vector, napi); + struct ixgbe_adapter *adapter = q_vector->adapter; + struct ixgbe_ring *ring; + int found; + + if (unlikely(!unsafe_to_remove)) { + unsafe_to_remove = 1; + if (!allow_unsafe_removal) { + pr_info("module may no longer be removed\n"); + try_module_get(THIS_MODULE); + } + } + + if (test_bit(__IXGBE_DOWN, &adapter->state)) + return LL_FLUSH_FAILED; + + if (!ixgbe_qv_lock_poll(q_vector)) + return LL_FLUSH_BUSY; + + ixgbe_for_each_ring(ring, q_vector->rx) { + found = ixgbe_clean_rx_irq(q_vector, ring, 4); + if (found) + break; + } + + ixgbe_qv_unlock_poll(q_vector); + + return LL_FLUSH_DONE; +} +#endif /* CONFIG_INET_LL_RX_POLL */ + /** * ixgbe_configure_msix - Configure MSI-X hardware * @adapter: board private structure @@ -2550,6 +2598,9 @@ int ixgbe_poll(struct napi_struct *napi, int budget) ixgbe_for_each_ring(ring, q_vector->tx) clean_complete &= !!ixgbe_clean_tx_irq(q_vector, ring); + if (!ixgbe_qv_lock_napi(q_vector)) + return budget; + /* attempt to distribute budget to each queue fairly, but don't allow * the budget to go below 1 because we'll exit polling */ if (q_vector->rx.count > 1) @@ -2558,9 +2609,10 @@ int ixgbe_poll(struct napi_struct *napi, int budget) per_ring_budget = budget; ixgbe_for_each_ring(ring, q_vector->rx) - clean_complete &= ixgbe_clean_rx_irq(q_vector, ring, - per_ring_budget); + clean_complete &= (ixgbe_clean_rx_irq(q_vector, ring, + per_ring_budget) < per_ring_budget); + ixgbe_qv_unlock_napi(q_vector); /* If all work not completed, return budget and keep polling */ if (!clean_complete) return budget; @@ -3747,16 +3799,25 @@ static void ixgbe_napi_enable_all(struct ixgbe_adapter *adapter) { int q_idx; - for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) + for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) { + ixgbe_qv_init_lock(adapter->q_vector[q_idx]); napi_enable(&adapter->q_vector[q_idx]->napi); + } } static void ixgbe_napi_disable_all(struct ixgbe_adapter *adapter) { int q_idx; - for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) + local_bh_disable(); /* for ixgbe_qv_lock_napi() */ + for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) { napi_disable(&adapter->q_vector[q_idx]->napi); + while (!ixgbe_qv_lock_napi(adapter->q_vector[q_idx])) { + pr_info("QV %d locked\n", q_idx); + mdelay(1); + } + } + local_bh_enable(); } #ifdef CONFIG_IXGBE_DCB @@ -7177,6 +7238,9 @@ static const struct net_device_ops ixgbe_netdev_ops = { #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = ixgbe_netpoll, #endif +#ifdef CONFIG_INET_LL_RX_POLL + .ndo_ll_poll = ixgbe_low_latency_recv, +#endif #ifdef IXGBE_FCOE .ndo_fcoe_ddp_setup = ixgbe_fcoe_ddp_get, .ndo_fcoe_ddp_target = ixgbe_fcoe_ddp_target,

[v3,net-next,3/4] ixgbe: Add support for ndo_ll_poll

Commit Message

Comments

Patch