| /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ |
| /* Copyright (c) 2019 Mellanox Technologies. */ |
| |
| #ifndef DIM_H |
| #define DIM_H |
| |
| #include <linux/bits.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/workqueue.h> |
| |
| /* |
| * Number of events between DIM iterations. |
| * Causes a moderation of the algorithm run. |
| */ |
| #define DIM_NEVENTS 64 |
| |
| /* |
| * Is a difference between values justifies taking an action. |
| * We consider 10% difference as significant. |
| */ |
| #define IS_SIGNIFICANT_DIFF(val, ref) \ |
| (((100UL * abs((val) - (ref))) / (ref)) > 10) |
| |
| /* |
| * Calculate the gap between two values. |
| * Take wrap-around and variable size into consideration. |
| */ |
| #define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \ |
| & (BIT_ULL(bits) - 1)) |
| |
| /** |
| * struct dim_cq_moder - Structure for CQ moderation values. |
| * Used for communications between DIM and its consumer. |
| * |
| * @usec: CQ timer suggestion (by DIM) |
| * @pkts: CQ packet counter suggestion (by DIM) |
| * @comps: Completion counter |
| * @cq_period_mode: CQ period count mode (from CQE/EQE) |
| */ |
| struct dim_cq_moder { |
| u16 usec; |
| u16 pkts; |
| u16 comps; |
| u8 cq_period_mode; |
| }; |
| |
| /** |
| * struct dim_sample - Structure for DIM sample data. |
| * Used for communications between DIM and its consumer. |
| * |
| * @time: Sample timestamp |
| * @pkt_ctr: Number of packets |
| * @byte_ctr: Number of bytes |
| * @event_ctr: Number of events |
| * @comp_ctr: Current completion counter |
| */ |
| struct dim_sample { |
| ktime_t time; |
| u32 pkt_ctr; |
| u32 byte_ctr; |
| u16 event_ctr; |
| u32 comp_ctr; |
| }; |
| |
| /** |
| * struct dim_stats - Structure for DIM stats. |
| * Used for holding current measured rates. |
| * |
| * @ppms: Packets per msec |
| * @bpms: Bytes per msec |
| * @epms: Events per msec |
| * @cpms: Completions per msec |
| * @cpe_ratio: Ratio of completions to events |
| */ |
| struct dim_stats { |
| int ppms; /* packets per msec */ |
| int bpms; /* bytes per msec */ |
| int epms; /* events per msec */ |
| int cpms; /* completions per msec */ |
| int cpe_ratio; /* ratio of completions to events */ |
| }; |
| |
| /** |
| * struct dim - Main structure for dynamic interrupt moderation (DIM). |
| * Used for holding all information about a specific DIM instance. |
| * |
| * @state: Algorithm state (see below) |
| * @prev_stats: Measured rates from previous iteration (for comparison) |
| * @start_sample: Sampled data at start of current iteration |
| * @measuring_sample: A &dim_sample that is used to update the current events |
| * @work: Work to perform on action required |
| * @priv: A pointer to the struct that points to dim |
| * @profile_ix: Current moderation profile |
| * @mode: CQ period count mode |
| * @tune_state: Algorithm tuning state (see below) |
| * @steps_right: Number of steps taken towards higher moderation |
| * @steps_left: Number of steps taken towards lower moderation |
| * @tired: Parking depth counter |
| */ |
| struct dim { |
| u8 state; |
| struct dim_stats prev_stats; |
| struct dim_sample start_sample; |
| struct dim_sample measuring_sample; |
| struct work_struct work; |
| void *priv; |
| u8 profile_ix; |
| u8 mode; |
| u8 tune_state; |
| u8 steps_right; |
| u8 steps_left; |
| u8 tired; |
| }; |
| |
| /** |
| * enum dim_cq_period_mode - Modes for CQ period count |
| * |
| * @DIM_CQ_PERIOD_MODE_START_FROM_EQE: Start counting from EQE |
| * @DIM_CQ_PERIOD_MODE_START_FROM_CQE: Start counting from CQE (implies timer reset) |
| * @DIM_CQ_PERIOD_NUM_MODES: Number of modes |
| */ |
| enum dim_cq_period_mode { |
| DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0, |
| DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1, |
| DIM_CQ_PERIOD_NUM_MODES |
| }; |
| |
| /** |
| * enum dim_state - DIM algorithm states |
| * |
| * These will determine if the algorithm is in a valid state to start an iteration. |
| * |
| * @DIM_START_MEASURE: This is the first iteration (also after applying a new profile) |
| * @DIM_MEASURE_IN_PROGRESS: Algorithm is already in progress - check if |
| * need to perform an action |
| * @DIM_APPLY_NEW_PROFILE: DIM consumer is currently applying a profile - no need to measure |
| */ |
| enum dim_state { |
| DIM_START_MEASURE, |
| DIM_MEASURE_IN_PROGRESS, |
| DIM_APPLY_NEW_PROFILE, |
| }; |
| |
| /** |
| * enum dim_tune_state - DIM algorithm tune states |
| * |
| * These will determine which action the algorithm should perform. |
| * |
| * @DIM_PARKING_ON_TOP: Algorithm found a local top point - exit on significant difference |
| * @DIM_PARKING_TIRED: Algorithm found a deep top point - don't exit if tired > 0 |
| * @DIM_GOING_RIGHT: Algorithm is currently trying higher moderation levels |
| * @DIM_GOING_LEFT: Algorithm is currently trying lower moderation levels |
| */ |
| enum dim_tune_state { |
| DIM_PARKING_ON_TOP, |
| DIM_PARKING_TIRED, |
| DIM_GOING_RIGHT, |
| DIM_GOING_LEFT, |
| }; |
| |
| /** |
| * enum dim_stats_state - DIM algorithm statistics states |
| * |
| * These will determine the verdict of current iteration. |
| * |
| * @DIM_STATS_WORSE: Current iteration shows worse performance than before |
| * @DIM_STATS_SAME: Current iteration shows same performance than before |
| * @DIM_STATS_BETTER: Current iteration shows better performance than before |
| */ |
| enum dim_stats_state { |
| DIM_STATS_WORSE, |
| DIM_STATS_SAME, |
| DIM_STATS_BETTER, |
| }; |
| |
| /** |
| * enum dim_step_result - DIM algorithm step results |
| * |
| * These describe the result of a step. |
| * |
| * @DIM_STEPPED: Performed a regular step |
| * @DIM_TOO_TIRED: Same kind of step was done multiple times - should go to |
| * tired parking |
| * @DIM_ON_EDGE: Stepped to the most left/right profile |
| */ |
| enum dim_step_result { |
| DIM_STEPPED, |
| DIM_TOO_TIRED, |
| DIM_ON_EDGE, |
| }; |
| |
| /** |
| * dim_on_top - check if current state is a good place to stop (top location) |
| * @dim: DIM context |
| * |
| * Check if current profile is a good place to park at. |
| * This will result in reducing the DIM checks frequency as we assume we |
| * shouldn't probably change profiles, unless traffic pattern wasn't changed. |
| */ |
| bool dim_on_top(struct dim *dim); |
| |
| /** |
| * dim_turn - change profile altering direction |
| * @dim: DIM context |
| * |
| * Go left if we were going right and vice-versa. |
| * Do nothing if currently parking. |
| */ |
| void dim_turn(struct dim *dim); |
| |
| /** |
| * dim_park_on_top - enter a parking state on a top location |
| * @dim: DIM context |
| * |
| * Enter parking state. |
| * Clear all movement history. |
| */ |
| void dim_park_on_top(struct dim *dim); |
| |
| /** |
| * dim_park_tired - enter a tired parking state |
| * @dim: DIM context |
| * |
| * Enter parking state. |
| * Clear all movement history and cause DIM checks frequency to reduce. |
| */ |
| void dim_park_tired(struct dim *dim); |
| |
| /** |
| * dim_calc_stats - calculate the difference between two samples |
| * @start: start sample |
| * @end: end sample |
| * @curr_stats: delta between samples |
| * |
| * Calculate the delta between two samples (in data rates). |
| * Takes into consideration counter wrap-around. |
| */ |
| void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, |
| struct dim_stats *curr_stats); |
| |
| /** |
| * dim_update_sample - set a sample's fields with given values |
| * @event_ctr: number of events to set |
| * @packets: number of packets to set |
| * @bytes: number of bytes to set |
| * @s: DIM sample |
| */ |
| static inline void |
| dim_update_sample(u16 event_ctr, u64 packets, u64 bytes, struct dim_sample *s) |
| { |
| s->time = ktime_get(); |
| s->pkt_ctr = packets; |
| s->byte_ctr = bytes; |
| s->event_ctr = event_ctr; |
| } |
| |
| /** |
| * dim_update_sample_with_comps - set a sample's fields with given |
| * values including the completion parameter |
| * @event_ctr: number of events to set |
| * @packets: number of packets to set |
| * @bytes: number of bytes to set |
| * @comps: number of completions to set |
| * @s: DIM sample |
| */ |
| static inline void |
| dim_update_sample_with_comps(u16 event_ctr, u64 packets, u64 bytes, u64 comps, |
| struct dim_sample *s) |
| { |
| dim_update_sample(event_ctr, packets, bytes, s); |
| s->comp_ctr = comps; |
| } |
| |
| /* Net DIM */ |
| |
| /** |
| * net_dim_get_rx_moderation - provide a CQ moderation object for the given RX profile |
| * @cq_period_mode: CQ period mode |
| * @ix: Profile index |
| */ |
| struct dim_cq_moder net_dim_get_rx_moderation(u8 cq_period_mode, int ix); |
| |
| /** |
| * net_dim_get_def_rx_moderation - provide the default RX moderation |
| * @cq_period_mode: CQ period mode |
| */ |
| struct dim_cq_moder net_dim_get_def_rx_moderation(u8 cq_period_mode); |
| |
| /** |
| * net_dim_get_tx_moderation - provide a CQ moderation object for the given TX profile |
| * @cq_period_mode: CQ period mode |
| * @ix: Profile index |
| */ |
| struct dim_cq_moder net_dim_get_tx_moderation(u8 cq_period_mode, int ix); |
| |
| /** |
| * net_dim_get_def_tx_moderation - provide the default TX moderation |
| * @cq_period_mode: CQ period mode |
| */ |
| struct dim_cq_moder net_dim_get_def_tx_moderation(u8 cq_period_mode); |
| |
| /** |
| * net_dim - main DIM algorithm entry point |
| * @dim: DIM instance information |
| * @end_sample: Current data measurement |
| * |
| * Called by the consumer. |
| * This is the main logic of the algorithm, where data is processed in order |
| * to decide on next required action. |
| */ |
| void net_dim(struct dim *dim, struct dim_sample end_sample); |
| |
| /* RDMA DIM */ |
| |
| /* |
| * RDMA DIM profile: |
| * profile size must be of RDMA_DIM_PARAMS_NUM_PROFILES. |
| */ |
| #define RDMA_DIM_PARAMS_NUM_PROFILES 9 |
| #define RDMA_DIM_START_PROFILE 0 |
| |
| /** |
| * rdma_dim - Runs the adaptive moderation. |
| * @dim: The moderation struct. |
| * @completions: The number of completions collected in this round. |
| * |
| * Each call to rdma_dim takes the latest amount of completions that |
| * have been collected and counts them as a new event. |
| * Once enough events have been collected the algorithm decides a new |
| * moderation level. |
| */ |
| void rdma_dim(struct dim *dim, u64 completions); |
| |
| #endif /* DIM_H */ |