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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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>
struct net_device;
/* Number of DIM profiles and period mode. */#define NET_DIM_PARAMS_NUM_PROFILES 5#define NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE 256#define NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE 128#define NET_DIM_DEF_PROFILE_CQE 1#define NET_DIM_DEF_PROFILE_EQE 1
/* * 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) \ ((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) * @rcu: for asynchronous kfree_rcu */struct dim_cq_moder { u16 usec; u16 pkts; u16 comps; u8 cq_period_mode; struct rcu_head rcu;};
#define DIM_PROFILE_RX BIT(0) /* support rx profile modification */#define DIM_PROFILE_TX BIT(1) /* support tx profile modification */
#define DIM_COALESCE_USEC BIT(0) /* support usec field modification */#define DIM_COALESCE_PKTS BIT(1) /* support pkts field modification */#define DIM_COALESCE_COMPS BIT(2) /* support comps field modification */
/** * struct dim_irq_moder - Structure for irq moderation information. * Used to collect irq moderation related information. * * @profile_flags: DIM_PROFILE_* * @coal_flags: DIM_COALESCE_* for Rx and Tx * @dim_rx_mode: Rx DIM period count mode: CQE or EQE * @dim_tx_mode: Tx DIM period count mode: CQE or EQE * @rx_profile: DIM profile list for Rx * @tx_profile: DIM profile list for Tx * @rx_dim_work: Rx DIM worker scheduled by net_dim() * @tx_dim_work: Tx DIM worker scheduled by net_dim() */struct dim_irq_moder { u8 profile_flags; u8 coal_flags; u8 dim_rx_mode; u8 dim_tx_mode; struct dim_cq_moder __rcu *rx_profile; struct dim_cq_moder __rcu *tx_profile; void (*rx_dim_work)(struct work_struct *work); void (*tx_dim_work)(struct work_struct *work);};
/** * 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,};
/** * net_dim_init_irq_moder - collect information to initialize irq moderation * @dev: target network device * @profile_flags: Rx or Tx profile modification capability * @coal_flags: irq moderation params flags * @rx_mode: CQ period mode for Rx * @tx_mode: CQ period mode for Tx * @rx_dim_work: Rx worker called after dim decision * @tx_dim_work: Tx worker called after dim decision * * Return: 0 on success or a negative error code. */int net_dim_init_irq_moder(struct net_device *dev, u8 profile_flags, u8 coal_flags, u8 rx_mode, u8 tx_mode, void (*rx_dim_work)(struct work_struct *work), void (*tx_dim_work)(struct work_struct *work));
/** * net_dim_free_irq_moder - free fields for irq moderation * @dev: target network device */void net_dim_free_irq_moder(struct net_device *dev);
/** * net_dim_setting - initialize DIM's cq mode and schedule worker * @dev: target network device * @dim: DIM context * @is_tx: true indicates the tx direction, false indicates the rx direction */void net_dim_setting(struct net_device *dev, struct dim *dim, bool is_tx);
/** * net_dim_work_cancel - synchronously cancel dim's worker * @dim: DIM context */void net_dim_work_cancel(struct dim *dim);
/** * net_dim_get_rx_irq_moder - get DIM rx results based on profile_ix * @dev: target network device * @dim: DIM context * * Return: DIM irq moderation */struct dim_cq_modernet_dim_get_rx_irq_moder(struct net_device *dev, struct dim *dim);
/** * net_dim_get_tx_irq_moder - get DIM tx results based on profile_ix * @dev: target network device * @dim: DIM context * * Return: DIM irq moderation */struct dim_cq_modernet_dim_get_tx_irq_moder(struct net_device *dev, struct dim *dim);
/** * net_dim_set_rx_mode - set DIM rx cq mode * @dev: target network device * @rx_mode: target rx cq mode */void net_dim_set_rx_mode(struct net_device *dev, u8 rx_mode);
/** * net_dim_set_tx_mode - set DIM tx cq mode * @dev: target network device * @tx_mode: target tx cq mode */void net_dim_set_tx_mode(struct net_device *dev, u8 tx_mode);
/** * 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. * Returned boolean indicates whether curr_stats are reliable. */bool dim_calc_stats(const struct dim_sample *start, const 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 voiddim_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 voiddim_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, const 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 */