| Message ID | 20210901044933.47230-1-kerneljasonxing@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v6] ixgbe: let the xdpdrv work with more than 64 cpus | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 16 of 16 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 1 this patch: 1 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | fail | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 232 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 1 this patch: 1 |
| netdev/header_inline | success | Link |
On 8/31/21 9:49 PM, kerneljasonxing@gmail.com wrote: > From: Jason Xing <xingwanli@kuaishou.com> > > Originally, ixgbe driver doesn't allow the mounting of xdpdrv if the > server is equipped with more than 64 cpus online. So it turns out that > the loading of xdpdrv causes the "NOMEM" failure. > > Actually, we can adjust the algorithm and then make it work through > mapping the current cpu to some xdp ring with the protect of @tx_lock. > > Here're some numbers before/after applying this patch with xdp-example > loaded on the eth0X: > > As client (tx path): > Before After > TCP_STREAM send-64 734.14 714.20 > TCP_STREAM send-128 1401.91 1395.05 > TCP_STREAM send-512 5311.67 5292.84 > TCP_STREAM send-1k 9277.40 9356.22 (not stable) > TCP_RR send-1 22559.75 21844.22 > TCP_RR send-128 23169.54 22725.13 > TCP_RR send-512 21670.91 21412.56 > > As server (rx path): > Before After > TCP_STREAM send-64 1416.49 1383.12 > TCP_STREAM send-128 3141.49 3055.50 > TCP_STREAM send-512 9488.73 9487.44 > TCP_STREAM send-1k 9491.17 9356.22 (not stable) > TCP_RR send-1 23617.74 23601.60 > ... > > Notice: the TCP_RR mode is unstable as the official document explaines. > > I tested many times with different parameters combined through netperf. > Though the result is not that accurate, I cannot see much influence on > this patch. The static key is places on the hot path, but it actually > shouldn't cause a huge regression theoretically. > > Fixes: 33fdc82f08 ("ixgbe: add support for XDP_TX action") > Reported-by: kernel test robot <lkp@intel.com> > Co-developed-by: Shujin Li <lishujin@kuaishou.com> > Signed-off-by: Shujin Li <lishujin@kuaishou.com> > Signed-off-by: Jason Xing <xingwanli@kuaishou.com> > --- > v6: > - Move the declaration of static-key to the proper position (Test Robot) > - Add reported-by tag (Jason) > - Add more detailed performance test results (Jason) > > v5: > - Change back to nr_cpu_ids (Eric) > > v4: > - Update the wrong commit messages. (Jason) > > v3: > - Change nr_cpu_ids to num_online_cpus() (Maciej) > - Rename MAX_XDP_QUEUES to IXGBE_MAX_XDP_QS (Maciej) > - Rename ixgbe_determine_xdp_cpu() to ixgbe_determine_xdp_q_idx() (Maciej) > - Wrap ixgbe_xdp_ring_update_tail() with lock into one function (Maciej) > > v2: > - Adjust cpu id in ixgbe_xdp_xmit(). (Jesper) > - Add a fallback path. (Maciej) > - Adjust other parts related to xdp ring. > --- > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 15 ++++- > drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c | 9 ++- > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 64 ++++++++++++++++------ > .../net/ethernet/intel/ixgbe/ixgbe_txrx_common.h | 1 + > drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 9 +-- > 5 files changed, 73 insertions(+), 25 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > index a604552..1dcddea 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > @@ -351,6 +351,7 @@ struct ixgbe_ring { > }; > u16 rx_offset; > struct xdp_rxq_info xdp_rxq; > + spinlock_t tx_lock; /* used in XDP mode */ > struct xsk_buff_pool *xsk_pool; > u16 ring_idx; /* {rx,tx,xdp}_ring back reference idx */ > u16 rx_buf_len; > @@ -375,11 +376,13 @@ enum ixgbe_ring_f_enum { > #define IXGBE_MAX_FCOE_INDICES 8 > #define MAX_RX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > #define MAX_TX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > -#define MAX_XDP_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > +#define IXGBE_MAX_XDP_QS (IXGBE_MAX_FDIR_INDICES + 1) > #define IXGBE_MAX_L2A_QUEUES 4 > #define IXGBE_BAD_L2A_QUEUE 3 > #define IXGBE_MAX_MACVLANS 63 > > +DECLARE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > + > struct ixgbe_ring_feature { > u16 limit; /* upper limit on feature indices */ > u16 indices; /* current value of indices */ > @@ -629,7 +632,7 @@ struct ixgbe_adapter { > > /* XDP */ > int num_xdp_queues; > - struct ixgbe_ring *xdp_ring[MAX_XDP_QUEUES]; > + struct ixgbe_ring *xdp_ring[IXGBE_MAX_XDP_QS]; > unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled rings */ > > /* TX */ > @@ -772,6 +775,14 @@ struct ixgbe_adapter { > #endif /* CONFIG_IXGBE_IPSEC */ > }; > > +static inline int ixgbe_determine_xdp_q_idx(int cpu) > +{ > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > + return cpu % IXGBE_MAX_XDP_QS; > + else > + return cpu; > +} > + > static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter) > { > switch (adapter->hw.mac.type) { > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > index 0218f6c..86b1116 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > @@ -299,7 +299,10 @@ static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter) > > static int ixgbe_xdp_queues(struct ixgbe_adapter *adapter) > { > - return adapter->xdp_prog ? nr_cpu_ids : 0; > + int queues; > + > + queues = min_t(int, IXGBE_MAX_XDP_QS, nr_cpu_ids); > + return adapter->xdp_prog ? queues : 0; > } > > #define IXGBE_RSS_64Q_MASK 0x3F > @@ -947,6 +950,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, > ring->count = adapter->tx_ring_count; > ring->queue_index = xdp_idx; > set_ring_xdp(ring); > + spin_lock_init(&ring->tx_lock); > > /* assign ring to adapter */ > WRITE_ONCE(adapter->xdp_ring[xdp_idx], ring); > @@ -1032,6 +1036,9 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx) > adapter->q_vector[v_idx] = NULL; > __netif_napi_del(&q_vector->napi); > > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > + static_branch_dec(&ixgbe_xdp_locking_key); > + > /* > * after a call to __netif_napi_del() napi may still be used and > * ixgbe_get_stats64() might access the rings on this vector, > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index 14aea40..bec29f5 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -165,6 +165,9 @@ static int ixgbe_notify_dca(struct notifier_block *, unsigned long event, > MODULE_DESCRIPTION("Intel(R) 10 Gigabit PCI Express Network Driver"); > MODULE_LICENSE("GPL v2"); > > +DEFINE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > +EXPORT_SYMBOL(ixgbe_xdp_locking_key); > + > static struct workqueue_struct *ixgbe_wq; > > static bool ixgbe_check_cfg_remove(struct ixgbe_hw *hw, struct pci_dev *pdev); > @@ -2422,13 +2425,10 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, > xdp_do_flush_map(); > > if (xdp_xmit & IXGBE_XDP_TX) { > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > - /* Force memory writes to complete before letting h/w > - * know there are new descriptors to fetch. > - */ > - wmb(); > - writel(ring->next_to_use, ring->tail); > + ixgbe_xdp_ring_update_tail_locked(ring); > } > > u64_stats_update_begin(&rx_ring->syncp); > @@ -6320,7 +6320,7 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter, > if (ixgbe_init_rss_key(adapter)) > return -ENOMEM; > > - adapter->af_xdp_zc_qps = bitmap_zalloc(MAX_XDP_QUEUES, GFP_KERNEL); > + adapter->af_xdp_zc_qps = bitmap_zalloc(IXGBE_MAX_XDP_QS, GFP_KERNEL); > if (!adapter->af_xdp_zc_qps) > return -ENOMEM; > > @@ -8539,21 +8539,32 @@ static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff *skb, > int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > struct xdp_frame *xdpf) > { > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > struct ixgbe_tx_buffer *tx_buffer; > union ixgbe_adv_tx_desc *tx_desc; > + struct ixgbe_ring *ring; > u32 len, cmd_type; > dma_addr_t dma; > + int index, ret; > u16 i; > > len = xdpf->len; > > - if (unlikely(!ixgbe_desc_unused(ring))) > - return IXGBE_XDP_CONSUMED; > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > + ring = adapter->xdp_ring[index]; > + > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > + spin_lock(&ring->tx_lock); > + > + if (unlikely(!ixgbe_desc_unused(ring))) { > + ret = IXGBE_XDP_CONSUMED; > + goto out; > + } > > dma = dma_map_single(ring->dev, xdpf->data, len, DMA_TO_DEVICE); > - if (dma_mapping_error(ring->dev, dma)) > - return IXGBE_XDP_CONSUMED; > + if (dma_mapping_error(ring->dev, dma)) { > + ret = IXGBE_XDP_CONSUMED; > + goto out; > + } > > /* record the location of the first descriptor for this packet */ > tx_buffer = &ring->tx_buffer_info[ring->next_to_use]; > @@ -8590,7 +8601,11 @@ int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > tx_buffer->next_to_watch = tx_desc; > ring->next_to_use = i; > > - return IXGBE_XDP_TX; > + ret = IXGBE_XDP_TX; > +out: > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > + spin_unlock(&ring->tx_lock); > + return ret; > } > > netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb, > @@ -10130,8 +10145,13 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) > return -EINVAL; > } > > - if (nr_cpu_ids > MAX_XDP_QUEUES) > + /* if the number of cpus is much larger than the maximum of queues, > + * we should stop it and then return with NOMEM like before. > + */ > + if (nr_cpu_ids > IXGBE_MAX_XDP_QS * 2) > return -ENOMEM; > + else if (nr_cpu_ids > IXGBE_MAX_XDP_QS) > + static_branch_inc(&ixgbe_xdp_locking_key); > > old_prog = xchg(&adapter->xdp_prog, prog); > need_reset = (!!prog != !!old_prog); > @@ -10195,12 +10215,22 @@ void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring) > writel(ring->next_to_use, ring->tail); > } > > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring) > +{ > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > + spin_lock(&ring->tx_lock); > + ixgbe_xdp_ring_update_tail(ring); > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > + spin_unlock(&ring->tx_lock); > +} It is not clear why you use a pair of spin_lock()/unlock for each ixgbe_xmit_xdp_ring() call, plus one other for ixgbe_xdp_ring_update_tail() I guess this could be factorized to a single spin lock/unlock in ixgbe_xdp_xmit(), and thus not have this ixgbe_xdp_ring_update_tail_locked() helper ? > + > static int ixgbe_xdp_xmit(struct net_device *dev, int n, > struct xdp_frame **frames, u32 flags) > { > struct ixgbe_adapter *adapter = netdev_priv(dev); > struct ixgbe_ring *ring; > int nxmit = 0; > + int index; > int i; > > if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) > @@ -10209,10 +10239,12 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) > return -EINVAL; > > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > + > /* During program transitions its possible adapter->xdp_prog is assigned > * but ring has not been configured yet. In this case simply abort xmit. > */ > - ring = adapter->xdp_prog ? adapter->xdp_ring[smp_processor_id()] : NULL; > + ring = adapter->xdp_prog ? adapter->xdp_ring[index] : NULL; > if (unlikely(!ring)) > return -ENXIO; > > @@ -10230,7 +10262,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > } > > if (unlikely(flags & XDP_XMIT_FLUSH)) > - ixgbe_xdp_ring_update_tail(ring); > + ixgbe_xdp_ring_update_tail_locked(ring); > > return nxmit; > } > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > index 2aeec78..f6426d9 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > @@ -23,6 +23,7 @@ void ixgbe_process_skb_fields(struct ixgbe_ring *rx_ring, > void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector, > struct sk_buff *skb); > void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring); > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring); > void ixgbe_irq_rearm_queues(struct ixgbe_adapter *adapter, u64 qmask); > > void ixgbe_txrx_ring_disable(struct ixgbe_adapter *adapter, int ring); > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > index b1d22e4..82d00e4 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > @@ -334,13 +334,10 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, > xdp_do_flush_map(); > > if (xdp_xmit & IXGBE_XDP_TX) { > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > - /* Force memory writes to complete before letting h/w > - * know there are new descriptors to fetch. > - */ > - wmb(); > - writel(ring->next_to_use, ring->tail); > + ixgbe_xdp_ring_update_tail_locked(ring); > } > > u64_stats_update_begin(&rx_ring->syncp); >
On Wed, Sep 1, 2021 at 1:13 PM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > > On 8/31/21 9:49 PM, kerneljasonxing@gmail.com wrote: > > From: Jason Xing <xingwanli@kuaishou.com> > > > > Originally, ixgbe driver doesn't allow the mounting of xdpdrv if the > > server is equipped with more than 64 cpus online. So it turns out that > > the loading of xdpdrv causes the "NOMEM" failure. > > > > Actually, we can adjust the algorithm and then make it work through > > mapping the current cpu to some xdp ring with the protect of @tx_lock. > > > > Here're some numbers before/after applying this patch with xdp-example > > loaded on the eth0X: > > > > As client (tx path): > > Before After > > TCP_STREAM send-64 734.14 714.20 > > TCP_STREAM send-128 1401.91 1395.05 > > TCP_STREAM send-512 5311.67 5292.84 > > TCP_STREAM send-1k 9277.40 9356.22 (not stable) > > TCP_RR send-1 22559.75 21844.22 > > TCP_RR send-128 23169.54 22725.13 > > TCP_RR send-512 21670.91 21412.56 > > > > As server (rx path): > > Before After > > TCP_STREAM send-64 1416.49 1383.12 > > TCP_STREAM send-128 3141.49 3055.50 > > TCP_STREAM send-512 9488.73 9487.44 > > TCP_STREAM send-1k 9491.17 9356.22 (not stable) > > TCP_RR send-1 23617.74 23601.60 > > ... > > > > Notice: the TCP_RR mode is unstable as the official document explaines. > > > > I tested many times with different parameters combined through netperf. > > Though the result is not that accurate, I cannot see much influence on > > this patch. The static key is places on the hot path, but it actually > > shouldn't cause a huge regression theoretically. > > > > Fixes: 33fdc82f08 ("ixgbe: add support for XDP_TX action") > > Reported-by: kernel test robot <lkp@intel.com> > > Co-developed-by: Shujin Li <lishujin@kuaishou.com> > > Signed-off-by: Shujin Li <lishujin@kuaishou.com> > > Signed-off-by: Jason Xing <xingwanli@kuaishou.com> > > --- > > v6: > > - Move the declaration of static-key to the proper position (Test Robot) > > - Add reported-by tag (Jason) > > - Add more detailed performance test results (Jason) > > > > v5: > > - Change back to nr_cpu_ids (Eric) > > > > v4: > > - Update the wrong commit messages. (Jason) > > > > v3: > > - Change nr_cpu_ids to num_online_cpus() (Maciej) > > - Rename MAX_XDP_QUEUES to IXGBE_MAX_XDP_QS (Maciej) > > - Rename ixgbe_determine_xdp_cpu() to ixgbe_determine_xdp_q_idx() (Maciej) > > - Wrap ixgbe_xdp_ring_update_tail() with lock into one function (Maciej) > > > > v2: > > - Adjust cpu id in ixgbe_xdp_xmit(). (Jesper) > > - Add a fallback path. (Maciej) > > - Adjust other parts related to xdp ring. > > --- > > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 15 ++++- > > drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c | 9 ++- > > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 64 ++++++++++++++++------ > > .../net/ethernet/intel/ixgbe/ixgbe_txrx_common.h | 1 + > > drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 9 +-- > > 5 files changed, 73 insertions(+), 25 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > index a604552..1dcddea 100644 > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > @@ -351,6 +351,7 @@ struct ixgbe_ring { > > }; > > u16 rx_offset; > > struct xdp_rxq_info xdp_rxq; > > + spinlock_t tx_lock; /* used in XDP mode */ > > struct xsk_buff_pool *xsk_pool; > > u16 ring_idx; /* {rx,tx,xdp}_ring back reference idx */ > > u16 rx_buf_len; > > @@ -375,11 +376,13 @@ enum ixgbe_ring_f_enum { > > #define IXGBE_MAX_FCOE_INDICES 8 > > #define MAX_RX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > #define MAX_TX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > -#define MAX_XDP_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > +#define IXGBE_MAX_XDP_QS (IXGBE_MAX_FDIR_INDICES + 1) > > #define IXGBE_MAX_L2A_QUEUES 4 > > #define IXGBE_BAD_L2A_QUEUE 3 > > #define IXGBE_MAX_MACVLANS 63 > > > > +DECLARE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > > + > > struct ixgbe_ring_feature { > > u16 limit; /* upper limit on feature indices */ > > u16 indices; /* current value of indices */ > > @@ -629,7 +632,7 @@ struct ixgbe_adapter { > > > > /* XDP */ > > int num_xdp_queues; > > - struct ixgbe_ring *xdp_ring[MAX_XDP_QUEUES]; > > + struct ixgbe_ring *xdp_ring[IXGBE_MAX_XDP_QS]; > > unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled rings */ > > > > /* TX */ > > @@ -772,6 +775,14 @@ struct ixgbe_adapter { > > #endif /* CONFIG_IXGBE_IPSEC */ > > }; > > > > +static inline int ixgbe_determine_xdp_q_idx(int cpu) > > +{ > > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > > + return cpu % IXGBE_MAX_XDP_QS; > > + else > > + return cpu; > > +} > > + > > static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter) > > { > > switch (adapter->hw.mac.type) { > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > index 0218f6c..86b1116 100644 > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > @@ -299,7 +299,10 @@ static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter) > > > > static int ixgbe_xdp_queues(struct ixgbe_adapter *adapter) > > { > > - return adapter->xdp_prog ? nr_cpu_ids : 0; > > + int queues; > > + > > + queues = min_t(int, IXGBE_MAX_XDP_QS, nr_cpu_ids); > > + return adapter->xdp_prog ? queues : 0; > > } > > > > #define IXGBE_RSS_64Q_MASK 0x3F > > @@ -947,6 +950,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, > > ring->count = adapter->tx_ring_count; > > ring->queue_index = xdp_idx; > > set_ring_xdp(ring); > > + spin_lock_init(&ring->tx_lock); > > > > /* assign ring to adapter */ > > WRITE_ONCE(adapter->xdp_ring[xdp_idx], ring); > > @@ -1032,6 +1036,9 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx) > > adapter->q_vector[v_idx] = NULL; > > __netif_napi_del(&q_vector->napi); > > > > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > > + static_branch_dec(&ixgbe_xdp_locking_key); > > + > > /* > > * after a call to __netif_napi_del() napi may still be used and > > * ixgbe_get_stats64() might access the rings on this vector, > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > index 14aea40..bec29f5 100644 > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > @@ -165,6 +165,9 @@ static int ixgbe_notify_dca(struct notifier_block *, unsigned long event, > > MODULE_DESCRIPTION("Intel(R) 10 Gigabit PCI Express Network Driver"); > > MODULE_LICENSE("GPL v2"); > > > > +DEFINE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > > +EXPORT_SYMBOL(ixgbe_xdp_locking_key); > > + > > static struct workqueue_struct *ixgbe_wq; > > > > static bool ixgbe_check_cfg_remove(struct ixgbe_hw *hw, struct pci_dev *pdev); > > @@ -2422,13 +2425,10 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, > > xdp_do_flush_map(); > > > > if (xdp_xmit & IXGBE_XDP_TX) { > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > > > - /* Force memory writes to complete before letting h/w > > - * know there are new descriptors to fetch. > > - */ > > - wmb(); > > - writel(ring->next_to_use, ring->tail); > > + ixgbe_xdp_ring_update_tail_locked(ring); > > } > > > > u64_stats_update_begin(&rx_ring->syncp); > > @@ -6320,7 +6320,7 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter, > > if (ixgbe_init_rss_key(adapter)) > > return -ENOMEM; > > > > - adapter->af_xdp_zc_qps = bitmap_zalloc(MAX_XDP_QUEUES, GFP_KERNEL); > > + adapter->af_xdp_zc_qps = bitmap_zalloc(IXGBE_MAX_XDP_QS, GFP_KERNEL); > > if (!adapter->af_xdp_zc_qps) > > return -ENOMEM; > > > > @@ -8539,21 +8539,32 @@ static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff *skb, > > int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > > struct xdp_frame *xdpf) > > { > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > struct ixgbe_tx_buffer *tx_buffer; > > union ixgbe_adv_tx_desc *tx_desc; > > + struct ixgbe_ring *ring; > > u32 len, cmd_type; > > dma_addr_t dma; > > + int index, ret; > > u16 i; > > > > len = xdpf->len; > > > > - if (unlikely(!ixgbe_desc_unused(ring))) > > - return IXGBE_XDP_CONSUMED; > > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > + ring = adapter->xdp_ring[index]; > > + > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > + spin_lock(&ring->tx_lock); > > + > > + if (unlikely(!ixgbe_desc_unused(ring))) { > > + ret = IXGBE_XDP_CONSUMED; > > + goto out; > > + } > > > > dma = dma_map_single(ring->dev, xdpf->data, len, DMA_TO_DEVICE); > > - if (dma_mapping_error(ring->dev, dma)) > > - return IXGBE_XDP_CONSUMED; > > + if (dma_mapping_error(ring->dev, dma)) { > > + ret = IXGBE_XDP_CONSUMED; > > + goto out; > > + } > > > > /* record the location of the first descriptor for this packet */ > > tx_buffer = &ring->tx_buffer_info[ring->next_to_use]; > > @@ -8590,7 +8601,11 @@ int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > > tx_buffer->next_to_watch = tx_desc; > > ring->next_to_use = i; > > > > - return IXGBE_XDP_TX; > > + ret = IXGBE_XDP_TX; > > +out: > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > + spin_unlock(&ring->tx_lock); > > + return ret; > > } > > > > netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb, > > @@ -10130,8 +10145,13 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) > > return -EINVAL; > > } > > > > - if (nr_cpu_ids > MAX_XDP_QUEUES) > > + /* if the number of cpus is much larger than the maximum of queues, > > + * we should stop it and then return with NOMEM like before. > > + */ > > + if (nr_cpu_ids > IXGBE_MAX_XDP_QS * 2) > > return -ENOMEM; > > + else if (nr_cpu_ids > IXGBE_MAX_XDP_QS) > > + static_branch_inc(&ixgbe_xdp_locking_key); > > > > old_prog = xchg(&adapter->xdp_prog, prog); > > need_reset = (!!prog != !!old_prog); > > @@ -10195,12 +10215,22 @@ void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring) > > writel(ring->next_to_use, ring->tail); > > } > > > > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring) > > +{ > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > + spin_lock(&ring->tx_lock); > > + ixgbe_xdp_ring_update_tail(ring); > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > + spin_unlock(&ring->tx_lock); > > +} > > It is not clear why you use a pair of spin_lock()/unlock for each ixgbe_xmit_xdp_ring() > call, plus one other for ixgbe_xdp_ring_update_tail() > > I guess this could be factorized to a single spin lock/unlock in ixgbe_xdp_xmit(), > and thus not have this ixgbe_xdp_ring_update_tail_locked() helper ? > I agree with what you said in ixgbe_xdp_xmit(). Two pairs of spin_lock/unlock could be factorized to a single one, which could decrease the times of calling lock and unlock. Thanks, Jason > > + > > static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > struct xdp_frame **frames, u32 flags) > > { > > struct ixgbe_adapter *adapter = netdev_priv(dev); > > struct ixgbe_ring *ring; > > int nxmit = 0; > > + int index; > > int i; > > > > if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) > > @@ -10209,10 +10239,12 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) > > return -EINVAL; > > > > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > + > > /* During program transitions its possible adapter->xdp_prog is assigned > > * but ring has not been configured yet. In this case simply abort xmit. > > */ > > - ring = adapter->xdp_prog ? adapter->xdp_ring[smp_processor_id()] : NULL; > > + ring = adapter->xdp_prog ? adapter->xdp_ring[index] : NULL; > > if (unlikely(!ring)) > > return -ENXIO; > > > > @@ -10230,7 +10262,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > } > > > > if (unlikely(flags & XDP_XMIT_FLUSH)) > > - ixgbe_xdp_ring_update_tail(ring); > > + ixgbe_xdp_ring_update_tail_locked(ring); > > > > return nxmit; > > } > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > index 2aeec78..f6426d9 100644 > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > @@ -23,6 +23,7 @@ void ixgbe_process_skb_fields(struct ixgbe_ring *rx_ring, > > void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector, > > struct sk_buff *skb); > > void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring); > > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring); > > void ixgbe_irq_rearm_queues(struct ixgbe_adapter *adapter, u64 qmask); > > > > void ixgbe_txrx_ring_disable(struct ixgbe_adapter *adapter, int ring); > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > index b1d22e4..82d00e4 100644 > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > @@ -334,13 +334,10 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, > > xdp_do_flush_map(); > > > > if (xdp_xmit & IXGBE_XDP_TX) { > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > > > - /* Force memory writes to complete before letting h/w > > - * know there are new descriptors to fetch. > > - */ > > - wmb(); > > - writel(ring->next_to_use, ring->tail); > > + ixgbe_xdp_ring_update_tail_locked(ring); > > } > > > > u64_stats_update_begin(&rx_ring->syncp); > >
On Wed, Sep 1, 2021 at 3:20 PM Jason Xing <kerneljasonxing@gmail.com> wrote: > > On Wed, Sep 1, 2021 at 1:13 PM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > > > > > > On 8/31/21 9:49 PM, kerneljasonxing@gmail.com wrote: > > > From: Jason Xing <xingwanli@kuaishou.com> > > > > > > Originally, ixgbe driver doesn't allow the mounting of xdpdrv if the > > > server is equipped with more than 64 cpus online. So it turns out that > > > the loading of xdpdrv causes the "NOMEM" failure. > > > > > > Actually, we can adjust the algorithm and then make it work through > > > mapping the current cpu to some xdp ring with the protect of @tx_lock. > > > > > > Here're some numbers before/after applying this patch with xdp-example > > > loaded on the eth0X: > > > > > > As client (tx path): > > > Before After > > > TCP_STREAM send-64 734.14 714.20 > > > TCP_STREAM send-128 1401.91 1395.05 > > > TCP_STREAM send-512 5311.67 5292.84 > > > TCP_STREAM send-1k 9277.40 9356.22 (not stable) > > > TCP_RR send-1 22559.75 21844.22 > > > TCP_RR send-128 23169.54 22725.13 > > > TCP_RR send-512 21670.91 21412.56 > > > > > > As server (rx path): > > > Before After > > > TCP_STREAM send-64 1416.49 1383.12 > > > TCP_STREAM send-128 3141.49 3055.50 > > > TCP_STREAM send-512 9488.73 9487.44 > > > TCP_STREAM send-1k 9491.17 9356.22 (not stable) > > > TCP_RR send-1 23617.74 23601.60 > > > ... > > > > > > Notice: the TCP_RR mode is unstable as the official document explaines. > > > > > > I tested many times with different parameters combined through netperf. > > > Though the result is not that accurate, I cannot see much influence on > > > this patch. The static key is places on the hot path, but it actually > > > shouldn't cause a huge regression theoretically. > > > > > > Fixes: 33fdc82f08 ("ixgbe: add support for XDP_TX action") > > > Reported-by: kernel test robot <lkp@intel.com> > > > Co-developed-by: Shujin Li <lishujin@kuaishou.com> > > > Signed-off-by: Shujin Li <lishujin@kuaishou.com> > > > Signed-off-by: Jason Xing <xingwanli@kuaishou.com> > > > --- > > > v6: > > > - Move the declaration of static-key to the proper position (Test Robot) > > > - Add reported-by tag (Jason) > > > - Add more detailed performance test results (Jason) > > > > > > v5: > > > - Change back to nr_cpu_ids (Eric) > > > > > > v4: > > > - Update the wrong commit messages. (Jason) > > > > > > v3: > > > - Change nr_cpu_ids to num_online_cpus() (Maciej) > > > - Rename MAX_XDP_QUEUES to IXGBE_MAX_XDP_QS (Maciej) > > > - Rename ixgbe_determine_xdp_cpu() to ixgbe_determine_xdp_q_idx() (Maciej) > > > - Wrap ixgbe_xdp_ring_update_tail() with lock into one function (Maciej) > > > > > > v2: > > > - Adjust cpu id in ixgbe_xdp_xmit(). (Jesper) > > > - Add a fallback path. (Maciej) > > > - Adjust other parts related to xdp ring. > > > --- > > > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 15 ++++- > > > drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c | 9 ++- > > > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 64 ++++++++++++++++------ > > > .../net/ethernet/intel/ixgbe/ixgbe_txrx_common.h | 1 + > > > drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 9 +-- > > > 5 files changed, 73 insertions(+), 25 deletions(-) > > > > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > > index a604552..1dcddea 100644 > > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > > > @@ -351,6 +351,7 @@ struct ixgbe_ring { > > > }; > > > u16 rx_offset; > > > struct xdp_rxq_info xdp_rxq; > > > + spinlock_t tx_lock; /* used in XDP mode */ > > > struct xsk_buff_pool *xsk_pool; > > > u16 ring_idx; /* {rx,tx,xdp}_ring back reference idx */ > > > u16 rx_buf_len; > > > @@ -375,11 +376,13 @@ enum ixgbe_ring_f_enum { > > > #define IXGBE_MAX_FCOE_INDICES 8 > > > #define MAX_RX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > > #define MAX_TX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > > -#define MAX_XDP_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) > > > +#define IXGBE_MAX_XDP_QS (IXGBE_MAX_FDIR_INDICES + 1) > > > #define IXGBE_MAX_L2A_QUEUES 4 > > > #define IXGBE_BAD_L2A_QUEUE 3 > > > #define IXGBE_MAX_MACVLANS 63 > > > > > > +DECLARE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > > > + > > > struct ixgbe_ring_feature { > > > u16 limit; /* upper limit on feature indices */ > > > u16 indices; /* current value of indices */ > > > @@ -629,7 +632,7 @@ struct ixgbe_adapter { > > > > > > /* XDP */ > > > int num_xdp_queues; > > > - struct ixgbe_ring *xdp_ring[MAX_XDP_QUEUES]; > > > + struct ixgbe_ring *xdp_ring[IXGBE_MAX_XDP_QS]; > > > unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled rings */ > > > > > > /* TX */ > > > @@ -772,6 +775,14 @@ struct ixgbe_adapter { > > > #endif /* CONFIG_IXGBE_IPSEC */ > > > }; > > > > > > +static inline int ixgbe_determine_xdp_q_idx(int cpu) > > > +{ > > > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > > > + return cpu % IXGBE_MAX_XDP_QS; > > > + else > > > + return cpu; > > > +} > > > + > > > static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter) > > > { > > > switch (adapter->hw.mac.type) { > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > > index 0218f6c..86b1116 100644 > > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c > > > @@ -299,7 +299,10 @@ static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter) > > > > > > static int ixgbe_xdp_queues(struct ixgbe_adapter *adapter) > > > { > > > - return adapter->xdp_prog ? nr_cpu_ids : 0; > > > + int queues; > > > + > > > + queues = min_t(int, IXGBE_MAX_XDP_QS, nr_cpu_ids); > > > + return adapter->xdp_prog ? queues : 0; > > > } > > > > > > #define IXGBE_RSS_64Q_MASK 0x3F > > > @@ -947,6 +950,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, > > > ring->count = adapter->tx_ring_count; > > > ring->queue_index = xdp_idx; > > > set_ring_xdp(ring); > > > + spin_lock_init(&ring->tx_lock); > > > > > > /* assign ring to adapter */ > > > WRITE_ONCE(adapter->xdp_ring[xdp_idx], ring); > > > @@ -1032,6 +1036,9 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx) > > > adapter->q_vector[v_idx] = NULL; > > > __netif_napi_del(&q_vector->napi); > > > > > > + if (static_key_enabled(&ixgbe_xdp_locking_key)) > > > + static_branch_dec(&ixgbe_xdp_locking_key); > > > + > > > /* > > > * after a call to __netif_napi_del() napi may still be used and > > > * ixgbe_get_stats64() might access the rings on this vector, > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > > index 14aea40..bec29f5 100644 > > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > > > @@ -165,6 +165,9 @@ static int ixgbe_notify_dca(struct notifier_block *, unsigned long event, > > > MODULE_DESCRIPTION("Intel(R) 10 Gigabit PCI Express Network Driver"); > > > MODULE_LICENSE("GPL v2"); > > > > > > +DEFINE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); > > > +EXPORT_SYMBOL(ixgbe_xdp_locking_key); > > > + > > > static struct workqueue_struct *ixgbe_wq; > > > > > > static bool ixgbe_check_cfg_remove(struct ixgbe_hw *hw, struct pci_dev *pdev); > > > @@ -2422,13 +2425,10 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, > > > xdp_do_flush_map(); > > > > > > if (xdp_xmit & IXGBE_XDP_TX) { > > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > > > > > - /* Force memory writes to complete before letting h/w > > > - * know there are new descriptors to fetch. > > > - */ > > > - wmb(); > > > - writel(ring->next_to_use, ring->tail); > > > + ixgbe_xdp_ring_update_tail_locked(ring); > > > } > > > > > > u64_stats_update_begin(&rx_ring->syncp); > > > @@ -6320,7 +6320,7 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter, > > > if (ixgbe_init_rss_key(adapter)) > > > return -ENOMEM; > > > > > > - adapter->af_xdp_zc_qps = bitmap_zalloc(MAX_XDP_QUEUES, GFP_KERNEL); > > > + adapter->af_xdp_zc_qps = bitmap_zalloc(IXGBE_MAX_XDP_QS, GFP_KERNEL); > > > if (!adapter->af_xdp_zc_qps) > > > return -ENOMEM; > > > > > > @@ -8539,21 +8539,32 @@ static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff *skb, > > > int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > > > struct xdp_frame *xdpf) > > > { > > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > > struct ixgbe_tx_buffer *tx_buffer; > > > union ixgbe_adv_tx_desc *tx_desc; > > > + struct ixgbe_ring *ring; > > > u32 len, cmd_type; > > > dma_addr_t dma; > > > + int index, ret; > > > u16 i; > > > > > > len = xdpf->len; > > > > > > - if (unlikely(!ixgbe_desc_unused(ring))) > > > - return IXGBE_XDP_CONSUMED; > > > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > > + ring = adapter->xdp_ring[index]; > > > + > > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > > + spin_lock(&ring->tx_lock); > > > + > > > + if (unlikely(!ixgbe_desc_unused(ring))) { > > > + ret = IXGBE_XDP_CONSUMED; > > > + goto out; > > > + } > > > > > > dma = dma_map_single(ring->dev, xdpf->data, len, DMA_TO_DEVICE); > > > - if (dma_mapping_error(ring->dev, dma)) > > > - return IXGBE_XDP_CONSUMED; > > > + if (dma_mapping_error(ring->dev, dma)) { > > > + ret = IXGBE_XDP_CONSUMED; > > > + goto out; > > > + } > > > > > > /* record the location of the first descriptor for this packet */ > > > tx_buffer = &ring->tx_buffer_info[ring->next_to_use]; > > > @@ -8590,7 +8601,11 @@ int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, > > > tx_buffer->next_to_watch = tx_desc; > > > ring->next_to_use = i; > > > > > > - return IXGBE_XDP_TX; > > > + ret = IXGBE_XDP_TX; > > > +out: > > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > > + spin_unlock(&ring->tx_lock); > > > + return ret; > > > } > > > > > > netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb, > > > @@ -10130,8 +10145,13 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) > > > return -EINVAL; > > > } > > > > > > - if (nr_cpu_ids > MAX_XDP_QUEUES) > > > + /* if the number of cpus is much larger than the maximum of queues, > > > + * we should stop it and then return with NOMEM like before. > > > + */ > > > + if (nr_cpu_ids > IXGBE_MAX_XDP_QS * 2) > > > return -ENOMEM; > > > + else if (nr_cpu_ids > IXGBE_MAX_XDP_QS) > > > + static_branch_inc(&ixgbe_xdp_locking_key); > > > > > > old_prog = xchg(&adapter->xdp_prog, prog); > > > need_reset = (!!prog != !!old_prog); > > > @@ -10195,12 +10215,22 @@ void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring) > > > writel(ring->next_to_use, ring->tail); > > > } > > > > > > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring) > > > +{ > > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > > + spin_lock(&ring->tx_lock); > > > + ixgbe_xdp_ring_update_tail(ring); > > > + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) > > > + spin_unlock(&ring->tx_lock); > > > +} > > > > It is not clear why you use a pair of spin_lock()/unlock for each ixgbe_xmit_xdp_ring() > > call, plus one other for ixgbe_xdp_ring_update_tail() > > > > I guess this could be factorized to a single spin lock/unlock in ixgbe_xdp_xmit(), > > and thus not have this ixgbe_xdp_ring_update_tail_locked() helper ? > > > > I agree with what you said in ixgbe_xdp_xmit(). Two pairs of > spin_lock/unlock could be factorized to a single one, which could > decrease the times of calling lock and unlock. > Wait, Eric. It seems that this could decrease the times of calling. However, this behaviour brings other changes about adding spin lock/unlock in ixgbe_run_xdp() and ixgbe_run_xdp_zc(). Is that necessary? Well, now, I'm a little bit convinced that what you said is the right way to go though I have to change some codes in ixgbe_run_xdp()/_zc(). > Thanks, > Jason > > > > + > > > static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > > struct xdp_frame **frames, u32 flags) > > > { > > > struct ixgbe_adapter *adapter = netdev_priv(dev); > > > struct ixgbe_ring *ring; > > > int nxmit = 0; > > > + int index; > > > int i; > > > > > > if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) > > > @@ -10209,10 +10239,12 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > > if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) > > > return -EINVAL; > > > > > > + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > > + > > > /* During program transitions its possible adapter->xdp_prog is assigned > > > * but ring has not been configured yet. In this case simply abort xmit. > > > */ > > > - ring = adapter->xdp_prog ? adapter->xdp_ring[smp_processor_id()] : NULL; > > > + ring = adapter->xdp_prog ? adapter->xdp_ring[index] : NULL; > > > if (unlikely(!ring)) > > > return -ENXIO; > > > > > > @@ -10230,7 +10262,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, > > > } > > > > > > if (unlikely(flags & XDP_XMIT_FLUSH)) > > > - ixgbe_xdp_ring_update_tail(ring); > > > + ixgbe_xdp_ring_update_tail_locked(ring); > > > > > > return nxmit; > > > } > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > > index 2aeec78..f6426d9 100644 > > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h > > > @@ -23,6 +23,7 @@ void ixgbe_process_skb_fields(struct ixgbe_ring *rx_ring, > > > void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector, > > > struct sk_buff *skb); > > > void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring); > > > +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring); > > > void ixgbe_irq_rearm_queues(struct ixgbe_adapter *adapter, u64 qmask); > > > > > > void ixgbe_txrx_ring_disable(struct ixgbe_adapter *adapter, int ring); > > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > > index b1d22e4..82d00e4 100644 > > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > > > @@ -334,13 +334,10 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, > > > xdp_do_flush_map(); > > > > > > if (xdp_xmit & IXGBE_XDP_TX) { > > > - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; > > > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > > > + struct ixgbe_ring *ring = adapter->xdp_ring[index]; > > > > > > - /* Force memory writes to complete before letting h/w > > > - * know there are new descriptors to fetch. > > > - */ > > > - wmb(); > > > - writel(ring->next_to_use, ring->tail); > > > + ixgbe_xdp_ring_update_tail_locked(ring); > > > } > > > > > > u64_stats_update_begin(&rx_ring->syncp); > > >
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h index a604552..1dcddea 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h @@ -351,6 +351,7 @@ struct ixgbe_ring { }; u16 rx_offset; struct xdp_rxq_info xdp_rxq; + spinlock_t tx_lock; /* used in XDP mode */ struct xsk_buff_pool *xsk_pool; u16 ring_idx; /* {rx,tx,xdp}_ring back reference idx */ u16 rx_buf_len; @@ -375,11 +376,13 @@ enum ixgbe_ring_f_enum { #define IXGBE_MAX_FCOE_INDICES 8 #define MAX_RX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) #define MAX_TX_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) -#define MAX_XDP_QUEUES (IXGBE_MAX_FDIR_INDICES + 1) +#define IXGBE_MAX_XDP_QS (IXGBE_MAX_FDIR_INDICES + 1) #define IXGBE_MAX_L2A_QUEUES 4 #define IXGBE_BAD_L2A_QUEUE 3 #define IXGBE_MAX_MACVLANS 63 +DECLARE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); + struct ixgbe_ring_feature { u16 limit; /* upper limit on feature indices */ u16 indices; /* current value of indices */ @@ -629,7 +632,7 @@ struct ixgbe_adapter { /* XDP */ int num_xdp_queues; - struct ixgbe_ring *xdp_ring[MAX_XDP_QUEUES]; + struct ixgbe_ring *xdp_ring[IXGBE_MAX_XDP_QS]; unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled rings */ /* TX */ @@ -772,6 +775,14 @@ struct ixgbe_adapter { #endif /* CONFIG_IXGBE_IPSEC */ }; +static inline int ixgbe_determine_xdp_q_idx(int cpu) +{ + if (static_key_enabled(&ixgbe_xdp_locking_key)) + return cpu % IXGBE_MAX_XDP_QS; + else + return cpu; +} + static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter) { switch (adapter->hw.mac.type) { diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c index 0218f6c..86b1116 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c @@ -299,7 +299,10 @@ static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter) static int ixgbe_xdp_queues(struct ixgbe_adapter *adapter) { - return adapter->xdp_prog ? nr_cpu_ids : 0; + int queues; + + queues = min_t(int, IXGBE_MAX_XDP_QS, nr_cpu_ids); + return adapter->xdp_prog ? queues : 0; } #define IXGBE_RSS_64Q_MASK 0x3F @@ -947,6 +950,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, ring->count = adapter->tx_ring_count; ring->queue_index = xdp_idx; set_ring_xdp(ring); + spin_lock_init(&ring->tx_lock); /* assign ring to adapter */ WRITE_ONCE(adapter->xdp_ring[xdp_idx], ring); @@ -1032,6 +1036,9 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx) adapter->q_vector[v_idx] = NULL; __netif_napi_del(&q_vector->napi); + if (static_key_enabled(&ixgbe_xdp_locking_key)) + static_branch_dec(&ixgbe_xdp_locking_key); + /* * after a call to __netif_napi_del() napi may still be used and * ixgbe_get_stats64() might access the rings on this vector, diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 14aea40..bec29f5 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -165,6 +165,9 @@ static int ixgbe_notify_dca(struct notifier_block *, unsigned long event, MODULE_DESCRIPTION("Intel(R) 10 Gigabit PCI Express Network Driver"); MODULE_LICENSE("GPL v2"); +DEFINE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); +EXPORT_SYMBOL(ixgbe_xdp_locking_key); + static struct workqueue_struct *ixgbe_wq; static bool ixgbe_check_cfg_remove(struct ixgbe_hw *hw, struct pci_dev *pdev); @@ -2422,13 +2425,10 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, xdp_do_flush_map(); if (xdp_xmit & IXGBE_XDP_TX) { - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); + struct ixgbe_ring *ring = adapter->xdp_ring[index]; - /* Force memory writes to complete before letting h/w - * know there are new descriptors to fetch. - */ - wmb(); - writel(ring->next_to_use, ring->tail); + ixgbe_xdp_ring_update_tail_locked(ring); } u64_stats_update_begin(&rx_ring->syncp); @@ -6320,7 +6320,7 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter, if (ixgbe_init_rss_key(adapter)) return -ENOMEM; - adapter->af_xdp_zc_qps = bitmap_zalloc(MAX_XDP_QUEUES, GFP_KERNEL); + adapter->af_xdp_zc_qps = bitmap_zalloc(IXGBE_MAX_XDP_QS, GFP_KERNEL); if (!adapter->af_xdp_zc_qps) return -ENOMEM; @@ -8539,21 +8539,32 @@ static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff *skb, int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, struct xdp_frame *xdpf) { - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; struct ixgbe_tx_buffer *tx_buffer; union ixgbe_adv_tx_desc *tx_desc; + struct ixgbe_ring *ring; u32 len, cmd_type; dma_addr_t dma; + int index, ret; u16 i; len = xdpf->len; - if (unlikely(!ixgbe_desc_unused(ring))) - return IXGBE_XDP_CONSUMED; + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); + ring = adapter->xdp_ring[index]; + + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) + spin_lock(&ring->tx_lock); + + if (unlikely(!ixgbe_desc_unused(ring))) { + ret = IXGBE_XDP_CONSUMED; + goto out; + } dma = dma_map_single(ring->dev, xdpf->data, len, DMA_TO_DEVICE); - if (dma_mapping_error(ring->dev, dma)) - return IXGBE_XDP_CONSUMED; + if (dma_mapping_error(ring->dev, dma)) { + ret = IXGBE_XDP_CONSUMED; + goto out; + } /* record the location of the first descriptor for this packet */ tx_buffer = &ring->tx_buffer_info[ring->next_to_use]; @@ -8590,7 +8601,11 @@ int ixgbe_xmit_xdp_ring(struct ixgbe_adapter *adapter, tx_buffer->next_to_watch = tx_desc; ring->next_to_use = i; - return IXGBE_XDP_TX; + ret = IXGBE_XDP_TX; +out: + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) + spin_unlock(&ring->tx_lock); + return ret; } netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb, @@ -10130,8 +10145,13 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) return -EINVAL; } - if (nr_cpu_ids > MAX_XDP_QUEUES) + /* if the number of cpus is much larger than the maximum of queues, + * we should stop it and then return with NOMEM like before. + */ + if (nr_cpu_ids > IXGBE_MAX_XDP_QS * 2) return -ENOMEM; + else if (nr_cpu_ids > IXGBE_MAX_XDP_QS) + static_branch_inc(&ixgbe_xdp_locking_key); old_prog = xchg(&adapter->xdp_prog, prog); need_reset = (!!prog != !!old_prog); @@ -10195,12 +10215,22 @@ void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring) writel(ring->next_to_use, ring->tail); } +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring) +{ + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) + spin_lock(&ring->tx_lock); + ixgbe_xdp_ring_update_tail(ring); + if (static_branch_unlikely(&ixgbe_xdp_locking_key)) + spin_unlock(&ring->tx_lock); +} + static int ixgbe_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags) { struct ixgbe_adapter *adapter = netdev_priv(dev); struct ixgbe_ring *ring; int nxmit = 0; + int index; int i; if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) @@ -10209,10 +10239,12 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) return -EINVAL; + index = ixgbe_determine_xdp_q_idx(smp_processor_id()); + /* During program transitions its possible adapter->xdp_prog is assigned * but ring has not been configured yet. In this case simply abort xmit. */ - ring = adapter->xdp_prog ? adapter->xdp_ring[smp_processor_id()] : NULL; + ring = adapter->xdp_prog ? adapter->xdp_ring[index] : NULL; if (unlikely(!ring)) return -ENXIO; @@ -10230,7 +10262,7 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, } if (unlikely(flags & XDP_XMIT_FLUSH)) - ixgbe_xdp_ring_update_tail(ring); + ixgbe_xdp_ring_update_tail_locked(ring); return nxmit; } diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h index 2aeec78..f6426d9 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_txrx_common.h @@ -23,6 +23,7 @@ void ixgbe_process_skb_fields(struct ixgbe_ring *rx_ring, void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector, struct sk_buff *skb); void ixgbe_xdp_ring_update_tail(struct ixgbe_ring *ring); +void ixgbe_xdp_ring_update_tail_locked(struct ixgbe_ring *ring); void ixgbe_irq_rearm_queues(struct ixgbe_adapter *adapter, u64 qmask); void ixgbe_txrx_ring_disable(struct ixgbe_adapter *adapter, int ring); diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c index b1d22e4..82d00e4 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c @@ -334,13 +334,10 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, xdp_do_flush_map(); if (xdp_xmit & IXGBE_XDP_TX) { - struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); + struct ixgbe_ring *ring = adapter->xdp_ring[index]; - /* Force memory writes to complete before letting h/w - * know there are new descriptors to fetch. - */ - wmb(); - writel(ring->next_to_use, ring->tail); + ixgbe_xdp_ring_update_tail_locked(ring); } u64_stats_update_begin(&rx_ring->syncp);