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linux/dim: Move logic to dim.h
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In preparation for supporting more implementations of the DIM
algorithm, I'm moving what would become common logic to a common
library. Downstream DIM implementations will use the common lib
for their implementation.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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Tal Gilboa authored and Saeed Mahameed committed Jun 25, 2019
1 parent cd6c84d commit 0e58983
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1 change: 1 addition & 0 deletions MAINTAINERS
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Original file line number Diff line number Diff line change
Expand Up @@ -5589,6 +5589,7 @@ DYNAMIC INTERRUPT MODERATION
M: Tal Gilboa <talgi@mellanox.com>
S: Maintained
F: include/linux/net_dim.h
F: include/linux/dim.h

DZ DECSTATION DZ11 SERIAL DRIVER
M: "Maciej W. Rozycki" <macro@linux-mips.org>
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153 changes: 153 additions & 0 deletions include/linux/dim.h
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@@ -0,0 +1,153 @@
/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
/* Copyright (c) 2019 Mellanox Technologies. */

#ifndef DIM_H
#define DIM_H

#include <linux/module.h>

#define NET_DIM_NEVENTS 64

/* more than 10% difference */
#define IS_SIGNIFICANT_DIFF(val, ref) \
(((100UL * abs((val) - (ref))) / (ref)) > 10)
#define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \
& (BIT_ULL(bits) - 1))

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 { /* Dynamic Interrupt 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
};

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,
};

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

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

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

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

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;
}

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);
}

#endif /* DIM_H */
148 changes: 2 additions & 146 deletions include/linux/net_dim.h
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Expand Up @@ -35,73 +35,10 @@
#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,
};
#include <linux/dim.h>

#define NET_DIM_PARAMS_NUM_PROFILES 5
/* Adaptive moderation profiles */
/* Netdev dynamic interrupt moderation profiles */
#define NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE 256
#define NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE 128
#define NET_DIM_DEF_PROFILE_CQE 1
Expand Down Expand Up @@ -188,36 +125,6 @@ net_dim_get_def_tx_moderation(u8 cq_period_mode)
return net_dim_get_tx_moderation(cq_period_mode, profile_ix);
}

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);
}
}

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;
}
}

static inline int net_dim_step(struct net_dim *dim)
{
if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
Expand Down Expand Up @@ -245,31 +152,13 @@ static inline int net_dim_step(struct net_dim *dim)
return NET_DIM_STEPPED;
}

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;
}

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;
}

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);
}

#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)
{
Expand Down Expand Up @@ -351,39 +240,6 @@ static inline bool net_dim_decision(struct net_dim_stats *curr_stats,
return dim->profile_ix != prev_ix;
}

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;
}

#define NET_DIM_NEVENTS 64
#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);
}

static inline void net_dim(struct net_dim *dim,
struct net_dim_sample end_sample)
{
Expand Down

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