cregit-Linux how code gets into the kernel

Release 4.16 include/linux/net_dim.h

Directory: include/linux
/*
 * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
 * Copyright (c) 2017-2018, Broadcom Limited. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef NET_DIM_H

#define NET_DIM_H

#include <linux/module.h>


struct net_dim_cq_moder {
	
u16 usec;
	
u16 pkts;
	
u8 cq_period_mode;
};


struct net_dim_sample {
	
ktime_t time;
	
u32     pkt_ctr;
	
u32     byte_ctr;
	
u16     event_ctr;
};


struct net_dim_stats {
	
int ppms; /* packets per msec */
	
int bpms; /* bytes per msec */
	
int epms; /* events per msec */
};


struct net_dim { /* Adaptive Moderation */
	
u8                                      state;
	
struct net_dim_stats                    prev_stats;
	
struct net_dim_sample                   start_sample;
	
struct work_struct                      work;
	
u8                                      profile_ix;
	
u8                                      mode;
	
u8                                      tune_state;
	
u8                                      steps_right;
	
u8                                      steps_left;
	
u8                                      tired;
};


enum {
	
NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0,
	
NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1,
	
NET_DIM_CQ_PERIOD_NUM_MODES
};

/* Adaptive moderation logic */

enum {
	
NET_DIM_START_MEASURE,
	
NET_DIM_MEASURE_IN_PROGRESS,
	
NET_DIM_APPLY_NEW_PROFILE,
};


enum {
	
NET_DIM_PARKING_ON_TOP,
	
NET_DIM_PARKING_TIRED,
	
NET_DIM_GOING_RIGHT,
	
NET_DIM_GOING_LEFT,
};


enum {
	
NET_DIM_STATS_WORSE,
	
NET_DIM_STATS_SAME,
	
NET_DIM_STATS_BETTER,
};


enum {
	
NET_DIM_STEPPED,
	
NET_DIM_TOO_TIRED,
	
NET_DIM_ON_EDGE,
};


#define NET_DIM_PARAMS_NUM_PROFILES 5
/* Adaptive moderation profiles */

#define NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE 256

#define NET_DIM_DEF_PROFILE_CQE 1

#define NET_DIM_DEF_PROFILE_EQE 1

/* All profiles sizes must be NET_PARAMS_DIM_NUM_PROFILES */

#define NET_DIM_EQE_PROFILES { \
        {1,   NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
        {8,   NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
        {64,  NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
        {128, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
        {256, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
}


#define NET_DIM_CQE_PROFILES { \
        {2,  256},             \
        {8,  128},             \
        {16, 64},              \
        {32, 64},              \
        {64, 64}               \
}

static const struct net_dim_cq_moder

profile[NET_DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
	NET_DIM_EQE_PROFILES,
	NET_DIM_CQE_PROFILES,
};


static inline struct net_dim_cq_moder net_dim_get_profile(u8 cq_period_mode, int ix) { struct net_dim_cq_moder cq_moder; cq_moder = profile[cq_period_mode][ix]; cq_moder.cq_period_mode = cq_period_mode; return cq_moder; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah1848.65%125.00%
Tal Gilboa1437.84%125.00%
Andy Gospodarek513.51%250.00%
Total37100.00%4100.00%


static inline struct net_dim_cq_moder net_dim_get_def_profile(u8 rx_cq_period_mode) { int default_profile_ix; if (rx_cq_period_mode == NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE) default_profile_ix = NET_DIM_DEF_PROFILE_CQE; else /* NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE */ default_profile_ix = NET_DIM_DEF_PROFILE_EQE; return net_dim_get_profile(rx_cq_period_mode, default_profile_ix); }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah2668.42%125.00%
Andy Gospodarek923.68%250.00%
Tal Gilboa37.89%125.00%
Total38100.00%4100.00%


static inline bool net_dim_on_top(struct net_dim *dim) { switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: return true; case NET_DIM_GOING_RIGHT: return (dim->steps_left > 1) && (dim->steps_right == 1); default: /* NET_DIM_GOING_LEFT */ return (dim->steps_right > 1) && (dim->steps_left == 1); } }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah5580.88%133.33%
Andy Gospodarek1319.12%266.67%
Total68100.00%3100.00%


static inline void net_dim_turn(struct net_dim *dim) { switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: break; case NET_DIM_GOING_RIGHT: dim->tune_state = NET_DIM_GOING_LEFT; dim->steps_left = 0; break; case NET_DIM_GOING_LEFT: dim->tune_state = NET_DIM_GOING_RIGHT; dim->steps_right = 0; break; } }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah4474.58%133.33%
Andy Gospodarek1525.42%266.67%
Total59100.00%3100.00%


static inline int net_dim_step(struct net_dim *dim) { if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2)) return NET_DIM_TOO_TIRED; switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: break; case NET_DIM_GOING_RIGHT: if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1)) return NET_DIM_ON_EDGE; dim->profile_ix++; dim->steps_right++; break; case NET_DIM_GOING_LEFT: if (dim->profile_ix == 0) return NET_DIM_ON_EDGE; dim->profile_ix--; dim->steps_left++; break; } dim->tired++; return NET_DIM_STEPPED; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah8177.88%133.33%
Andy Gospodarek2322.12%266.67%
Total104100.00%3100.00%


static inline void net_dim_park_on_top(struct net_dim *dim) { dim->steps_right = 0; dim->steps_left = 0; dim->tired = 0; dim->tune_state = NET_DIM_PARKING_ON_TOP; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah2775.00%133.33%
Andy Gospodarek925.00%266.67%
Total36100.00%3100.00%


static inline void net_dim_park_tired(struct net_dim *dim) { dim->steps_right = 0; dim->steps_left = 0; dim->tune_state = NET_DIM_PARKING_TIRED; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah2273.33%133.33%
Andy Gospodarek826.67%266.67%
Total30100.00%3100.00%


static inline void net_dim_exit_parking(struct net_dim *dim) { dim->tune_state = dim->profile_ix ? NET_DIM_GOING_LEFT : NET_DIM_GOING_RIGHT; net_dim_step(dim); }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah1965.52%133.33%
Andy Gospodarek1034.48%266.67%
Total29100.00%3100.00%

#define IS_SIGNIFICANT_DIFF(val, ref) \ (((100UL * abs((val) - (ref))) / (ref)) > 10) /* more than 10% difference */
static inline int net_dim_stats_compare(struct net_dim_stats *curr, struct net_dim_stats *prev) { if (!prev->bpms) return curr->bpms ? NET_DIM_STATS_BETTER : NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms)) return (curr->bpms > prev->bpms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; if (!prev->ppms) return curr->ppms ? NET_DIM_STATS_BETTER : NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms)) return (curr->ppms > prev->ppms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; if (!prev->epms) return NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms)) return (curr->epms < prev->epms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; return NET_DIM_STATS_SAME; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah6645.21%120.00%
Tal Gilboa4128.08%120.00%
Talat Batheesh2617.81%120.00%
Andy Gospodarek138.90%240.00%
Total146100.00%5100.00%


static inline bool net_dim_decision(struct net_dim_stats *curr_stats, struct net_dim *dim) { int prev_state = dim->tune_state; int prev_ix = dim->profile_ix; int stats_res; int step_res; switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats); if (stats_res != NET_DIM_STATS_SAME) net_dim_exit_parking(dim); break; case NET_DIM_PARKING_TIRED: dim->tired--; if (!dim->tired) net_dim_exit_parking(dim); break; case NET_DIM_GOING_RIGHT: case NET_DIM_GOING_LEFT: stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats); if (stats_res != NET_DIM_STATS_BETTER) net_dim_turn(dim); if (net_dim_on_top(dim)) { net_dim_park_on_top(dim); break; } step_res = net_dim_step(dim); switch (step_res) { case NET_DIM_ON_EDGE: net_dim_park_on_top(dim); break; case NET_DIM_TOO_TIRED: net_dim_park_tired(dim); break; } break; } if ((prev_state != NET_DIM_PARKING_ON_TOP) || (dim->tune_state != NET_DIM_PARKING_ON_TOP)) dim->prev_stats = *curr_stats; return dim->profile_ix != prev_ix; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah15678.39%133.33%
Andy Gospodarek4321.61%266.67%
Total199100.00%3100.00%


static inline void net_dim_sample(u16 event_ctr, u64 packets, u64 bytes, struct net_dim_sample *s) { s->time = ktime_get(); s->pkt_ctr = packets; s->byte_ctr = bytes; s->event_ctr = event_ctr; }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah2963.04%120.00%
Andy Gospodarek1123.91%360.00%
Tal Gilboa613.04%120.00%
Total46100.00%5100.00%

#define NET_DIM_NEVENTS 64 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) #define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) & (BIT_ULL(bits) - 1))
static inline void net_dim_calc_stats(struct net_dim_sample *start, struct net_dim_sample *end, struct net_dim_stats *curr_stats) { /* u32 holds up to 71 minutes, should be enough */ u32 delta_us = ktime_us_delta(end->time, start->time); u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr); u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr, start->byte_ctr); if (!delta_us) return; curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us); curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us); curr_stats->epms = DIV_ROUND_UP(NET_DIM_NEVENTS * USEC_PER_MSEC, delta_us); }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah6453.33%120.00%
Tal Gilboa5041.67%240.00%
Andy Gospodarek65.00%240.00%
Total120100.00%5100.00%


static inline void net_dim(struct net_dim *dim, struct net_dim_sample end_sample) { struct net_dim_stats curr_stats; u16 nevents; switch (dim->state) { case NET_DIM_MEASURE_IN_PROGRESS: nevents = BIT_GAP(BITS_PER_TYPE(u16), end_sample.event_ctr, dim->start_sample.event_ctr); if (nevents < NET_DIM_NEVENTS) break; net_dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats); if (net_dim_decision(&curr_stats, dim)) { dim->state = NET_DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); break; } /* fall through */ case NET_DIM_START_MEASURE: dim->state = NET_DIM_MEASURE_IN_PROGRESS; break; case NET_DIM_APPLY_NEW_PROFILE: break; } }

Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah8169.23%116.67%
Andy Gospodarek2723.08%466.67%
Tal Gilboa97.69%116.67%
Total117100.00%6100.00%

#endif /* NET_DIM_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Gil Rockah72157.31%19.09%
Andy Gospodarek35928.54%545.45%
Tal Gilboa15212.08%436.36%
Talat Batheesh262.07%19.09%
Total1258100.00%11100.00%
Directory: include/linux
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