Commit 0e58983d authored by Tal Gilboa's avatar Tal Gilboa Committed by Saeed Mahameed
Browse files

linux/dim: Move logic to dim.h 



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: default avatarTal Gilboa <talgi@mellanox.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
parent cd6c84d8

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -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>

include/linux/dim.h

0 → 100644
+153 −0
Original line number Diff line number Diff line 
/* 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 */

include/linux/net_dim.h

+2 −146
Original line number Diff line number Diff line
@@ -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
@@ -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))
@@ -245,21 +152,6 @@ 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 :
@@ -267,9 +159,6 @@ static inline void net_dim_exit_parking(struct net_dim *dim) 
	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)

{
@@ -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)

{