From 02d92f7903647119e125b24f5470f96cee0d4b4b Mon Sep 17 00:00:00 2001 From: Saeed Mahameed Date: Fri, 19 Jan 2018 16:13:01 -0800 Subject: net/mlx5: CQ Database per EQ Before this patch the driver had one CQ database protected via one spinlock, this spinlock is meant to synchronize between CQ adding/removing and CQ IRQ interrupt handling. On a system with large number of CPUs and on a work load that requires lots of interrupts, this global spinlock becomes a very nasty hotspot and introduces a contention between the active cores, which will significantly hurt performance and becomes a bottleneck that prevents seamless cpu scaling. To solve this we simply move the CQ database and its spinlock to be per EQ (IRQ), thus per core. Tested with: system: 2 sockets, 14 cores per socket, hyperthreading, 2x14x2=56 cores netperf command: ./super_netperf 200 -P 0 -t TCP_RR -H -l 30 -- -r 300,300 -o -s 1M,1M -S 1M,1M WITHOUT THIS PATCH: Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 4.32 0.00 36.15 0.09 0.00 34.02 0.00 0.00 0.00 25.41 Samples: 2M of event 'cycles:pp', Event count (approx.): 1554616897271 Overhead Command Shared Object Symbol + 14.28% swapper [kernel.vmlinux] [k] intel_idle + 12.25% swapper [kernel.vmlinux] [k] queued_spin_lock_slowpath + 10.29% netserver [kernel.vmlinux] [k] queued_spin_lock_slowpath + 1.32% netserver [kernel.vmlinux] [k] mlx5e_xmit WITH THIS PATCH: Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 4.27 0.00 34.31 0.01 0.00 18.71 0.00 0.00 0.00 42.69 Samples: 2M of event 'cycles:pp', Event count (approx.): 1498132937483 Overhead Command Shared Object Symbol + 23.33% swapper [kernel.vmlinux] [k] intel_idle + 1.69% netserver [kernel.vmlinux] [k] mlx5e_xmit Tested-by: Song Liu Signed-off-by: Saeed Mahameed Reviewed-by: Gal Pressman --- include/linux/mlx5/cq.h | 3 +-- include/linux/mlx5/driver.h | 22 +++++++++------------- 2 files changed, 10 insertions(+), 15 deletions(-) (limited to 'include/linux/mlx5') diff --git a/include/linux/mlx5/cq.h b/include/linux/mlx5/cq.h index 48c181a2acc9..06ba425a6ad7 100644 --- a/include/linux/mlx5/cq.h +++ b/include/linux/mlx5/cq.h @@ -60,6 +60,7 @@ struct mlx5_core_cq { } tasklet_ctx; int reset_notify_added; struct list_head reset_notify; + struct mlx5_eq *eq; }; @@ -171,8 +172,6 @@ static inline void mlx5_cq_arm(struct mlx5_core_cq *cq, u32 cmd, mlx5_write64(doorbell, uar_page + MLX5_CQ_DOORBELL, NULL); } -int mlx5_init_cq_table(struct mlx5_core_dev *dev); -void mlx5_cleanup_cq_table(struct mlx5_core_dev *dev); int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq, u32 *in, int inlen); int mlx5_core_destroy_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq); diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 6ed79a8a8318..96e003db2bcd 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -375,8 +375,15 @@ struct mlx5_eq_pagefault { mempool_t *pool; }; +struct mlx5_cq_table { + /* protect radix tree */ + spinlock_t lock; + struct radix_tree_root tree; +}; + struct mlx5_eq { struct mlx5_core_dev *dev; + struct mlx5_cq_table cq_table; __be32 __iomem *doorbell; u32 cons_index; struct mlx5_buf buf; @@ -526,13 +533,6 @@ struct mlx5_core_health { struct delayed_work recover_work; }; -struct mlx5_cq_table { - /* protect radix tree - */ - spinlock_t lock; - struct radix_tree_root tree; -}; - struct mlx5_qp_table { /* protect radix tree */ @@ -654,10 +654,6 @@ struct mlx5_priv { struct dentry *cmdif_debugfs; /* end: qp staff */ - /* start: cq staff */ - struct mlx5_cq_table cq_table; - /* end: cq staff */ - /* start: mkey staff */ struct mlx5_mkey_table mkey_table; /* end: mkey staff */ @@ -1053,12 +1049,12 @@ int mlx5_eq_init(struct mlx5_core_dev *dev); void mlx5_eq_cleanup(struct mlx5_core_dev *dev); void mlx5_fill_page_array(struct mlx5_buf *buf, __be64 *pas); void mlx5_fill_page_frag_array(struct mlx5_frag_buf *frag_buf, __be64 *pas); -void mlx5_cq_completion(struct mlx5_core_dev *dev, u32 cqn); +void mlx5_cq_completion(struct mlx5_eq *eq, u32 cqn); void mlx5_rsc_event(struct mlx5_core_dev *dev, u32 rsn, int event_type); void mlx5_srq_event(struct mlx5_core_dev *dev, u32 srqn, int event_type); struct mlx5_core_srq *mlx5_core_get_srq(struct mlx5_core_dev *dev, u32 srqn); void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool forced); -void mlx5_cq_event(struct mlx5_core_dev *dev, u32 cqn, int event_type); +void mlx5_cq_event(struct mlx5_eq *eq, u32 cqn, int event_type); int mlx5_create_map_eq(struct mlx5_core_dev *dev, struct mlx5_eq *eq, u8 vecidx, int nent, u64 mask, const char *name, enum mlx5_eq_type type); -- cgit v1.2.3