Re: [PATCH v4] ixgbe: let the xdpdrv work with more than 64 cpus
From: Eric Dumazet <hidden>
Date: 2021-08-26 16:18:27
Also in:
bpf, intel-wired-lan, lkml
On 8/26/21 7:16 AM, kerneljasonxing@gmail.com wrote:
From: Jason Xing <redacted> 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. v4: - Update the wrong commit messages. (Jason) v3: - Change nr_cpu_ids to num_online_cpus() (Maciej)
I suspect this is wrong.
quoted hunk ↗ jump to hunk
- 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. Fixes: 33fdc82f08 ("ixgbe: add support for XDP_TX action") Co-developed-by: Shujin Li <redacted> Signed-off-by: Shujin Li <redacted> Signed-off-by: Jason Xing <redacted> --- 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..5f7f181 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h@@ -82,6 +82,8 @@ #define IXGBE_2K_TOO_SMALL_WITH_PADDING \ ((NET_SKB_PAD + IXGBE_RXBUFFER_1536) > SKB_WITH_OVERHEAD(IXGBE_RXBUFFER_2K)) +DECLARE_STATIC_KEY_FALSE(ixgbe_xdp_locking_key); + static inline int ixgbe_compute_pad(int rx_buf_len) { int page_size, pad_size;@@ -351,6 +353,7 @@ 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;@@ -375,7 +378,7 @@ 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@@ -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;
Even if num_online_cpus() is 8, the returned cpu here could be 0, 32, 64, 96, 128, 161, 197, 224 Are we sure this will still be ok ?
quoted hunk ↗ jump to hunk
+} + 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..884bf99 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, num_online_cpus());
num_online_cpus() might change later...
quoted hunk ↗ jump to hunk
+ 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); + /*