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linux/dim: Move implementation to .c files

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Moved all logic from dim.h and net_dim.h to dim.c and net_dim.c.
This is both more structurally appealing and would allow to only
expose externally used functions.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
This commit is contained in:
Tal Gilboa 2019-01-10 17:33:17 +02:00 committed by Saeed Mahameed
parent 8960b38932
commit 4f75da3666
17 changed files with 546 additions and 344 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
MAINTAINERS
View file

@ -5588,8 +5588,8 @@ F: include/linux/dynamic_debug.h
DYNAMIC INTERRUPT MODERATION
M: Tal Gilboa <talgi@mellanox.com>
S: Maintained
F: include/linux/net_dim.h
F: include/linux/dim.h
F: lib/dim/
DZ DECSTATION DZ11 SERIAL DRIVER
M: "Maciej W. Rozycki" <macro@linux-mips.org>

1
drivers/net/ethernet/broadcom/Kconfig
View file

@ -8,6 +8,7 @@ config NET_VENDOR_BROADCOM
default y
depends on (SSB_POSSIBLE && HAS_DMA) || PCI || BCM63XX || \
SIBYTE_SB1xxx_SOC
select DIMLIB
---help---
If you have a network (Ethernet) chipset belonging to this class,
say Y.

2
drivers/net/ethernet/broadcom/bcmsysport.h
View file

@ -14,7 +14,7 @@
#include <linux/bitmap.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/net_dim.h>
#include <linux/dim.h>
/* Receive/transmit descriptor format */
#define DESC_ADDR_HI_STATUS_LEN 0x00

2
drivers/net/ethernet/broadcom/bnxt/bnxt.h
View file

@ -23,7 +23,7 @@
#include <net/devlink.h>
#include <net/dst_metadata.h>
#include <net/xdp.h>
#include <linux/net_dim.h>
#include <linux/dim.h>
struct tx_bd {
__le32 tx_bd_len_flags_type;

2
drivers/net/ethernet/broadcom/bnxt/bnxt_debugfs.c
View file

@ -11,7 +11,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include "bnxt_hsi.h"
#include <linux/net_dim.h>
#include <linux/dim.h>
#include "bnxt.h"
#include "bnxt_debugfs.h"

2
drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
View file

@ -7,7 +7,7 @@
* the Free Software Foundation.
*/
#include <linux/net_dim.h>
#include <linux/dim.h>
#include "bnxt_hsi.h"
#include "bnxt.h"

2
drivers/net/ethernet/broadcom/genet/bcmgenet.h
View file

@ -16,7 +16,7 @@
#include <linux/mii.h>
#include <linux/if_vlan.h>
#include <linux/phy.h>
#include <linux/net_dim.h>
#include <linux/dim.h>
/* total number of Buffer Descriptors, same for Rx/Tx */
#define TOTAL_DESC 256

1
drivers/net/ethernet/mellanox/mlx5/core/Kconfig
View file

@ -34,6 +34,7 @@ config MLX5_CORE_EN
depends on NETDEVICES && ETHERNET && INET && PCI && MLX5_CORE
depends on IPV6=y || IPV6=n || MLX5_CORE=m
select PAGE_POOL
select DIMLIB
default n
---help---
Ethernet support in Mellanox Technologies ConnectX-4 NIC.

2
drivers/net/ethernet/mellanox/mlx5/core/en.h
View file

@ -48,7 +48,7 @@
#include <linux/rhashtable.h>
#include <net/switchdev.h>
#include <net/xdp.h>
#include <linux/net_dim.h>
#include <linux/dim.h>
#include <linux/bits.h>
#include "wq.h"
#include "mlx5_core.h"

2
drivers/net/ethernet/mellanox/mlx5/core/en_dim.c
View file

@ -30,7 +30,7 @@
* SOFTWARE.
*/
#include <linux/net_dim.h>
#include <linux/dim.h>
#include "en.h"
static void

317
include/linux/dim.h
View file

@ -6,20 +6,49 @@
#include <linux/module.h>
/**
* Number of events between DIM iterations.
* Causes a moderation of the algorithm run.
*/
#define DIM_NEVENTS 64
/* more than 10% difference */
/**
* 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)
#define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \
& (BIT_ULL(bits) - 1))
/**
* 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))
/**
* 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)
* @cq_period_mode: CQ priod count mode (from CQE/EQE)
*/
struct dim_cq_moder {
u16 usec;
u16 pkts;
u8 cq_period_mode;
};
/**
* 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
*/
struct dim_sample {
ktime_t time;
u32 pkt_ctr;
@ -27,13 +56,36 @@ struct dim_sample {
u16 event_ctr;
};
/**
* Structure for DIM stats.
* Used for holding current measured rates.
*
* @ppms: Packets per msec
* @bpms: Bytes per msec
* @epms: Events per msec
*/
struct dim_stats {
int ppms; /* packets per msec */
int bpms; /* bytes per msec */
int epms; /* events per msec */
int ppms;
int bpms;
int epms;
};
struct dim { /* Dynamic Interrupt Moderation */
/**
* 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
* @work: Work to perform on action required
* @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;
@ -46,18 +98,49 @@ struct dim { /* Dynamic Interrupt Moderation */
u8 tired;
};
/**
* enum dim_cq_period_mode
*
* These are the 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_START_FROM_EQE = 0x0,
DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1,
DIM_CQ_PERIOD_NUM_MODES
};
/**
* enum dim_state
*
* These are the 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_START_MEASURE,
DIM_MEASURE_IN_PROGRESS,
DIM_APPLY_NEW_PROFILE,
};
/**
* enum dim_tune_state
*
* These are the 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_PARKING_ON_TOP,
DIM_PARKING_TIRED,
@ -65,63 +148,95 @@ enum {
DIM_GOING_LEFT,
};
/**
* enum dim_stats_state
*
* These are the DIM algorithm statistics states.
* These will determine the verdict of current iteration.
*
* @DIM_STATS_WORSE: Current iteration shows worse performance than before
* @DIM_STATS_WORSE: Current iteration shows same performance than before
* @DIM_STATS_WORSE: Current iteration shows better performance than before
*/
enum {
DIM_STATS_WORSE,
DIM_STATS_SAME,
DIM_STATS_BETTER,
};
/**
* enum dim_step_result
*
* These are the 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_STEPPED,
DIM_TOO_TIRED,
DIM_ON_EDGE,
};
static inline bool dim_on_top(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
return true;
case DIM_GOING_RIGHT:
return (dim->steps_left > 1) && (dim->steps_right == 1);
default: /* DIM_GOING_LEFT */
return (dim->steps_right > 1) && (dim->steps_left == 1);
}
}
/**
* 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);
static inline void dim_turn(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
break;
case DIM_GOING_RIGHT:
dim->tune_state = DIM_GOING_LEFT;
dim->steps_left = 0;
break;
case DIM_GOING_LEFT:
dim->tune_state = DIM_GOING_RIGHT;
dim->steps_right = 0;
break;
}
}
/**
* dim_turn - change profile alterning 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);
static inline void dim_park_on_top(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tired = 0;
dim->tune_state = DIM_PARKING_ON_TOP;
}
/**
* 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);
static inline void dim_park_tired(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tune_state = DIM_PARKING_TIRED;
}
/**
* 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 give 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)
{
@ -131,23 +246,99 @@ dim_update_sample(u16 event_ctr, u64 packets, u64 bytes, struct dim_sample *s)
s->event_ctr = event_ctr;
}
static inline void
dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
struct 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);
/* Net DIM */
if (!delta_us)
return;
/*
* Net DIM profiles:
* There are different set of profiles for each CQ period mode.
* There are different set of profiles for RX/TX CQs.
* Each profile size must be of NET_DIM_PARAMS_NUM_PROFILES
*/
#define NET_DIM_PARAMS_NUM_PROFILES 5
#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
#define NET_DIM_DEF_PROFILE_EQE 1
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(DIM_NEVENTS * USEC_PER_MSEC,
delta_us);
#define NET_DIM_RX_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_RX_CQE_PROFILES { \
{2, 256}, \
{8, 128}, \
{16, 64}, \
{32, 64}, \
{64, 64} \
}
#define NET_DIM_TX_EQE_PROFILES { \
{1, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{8, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{32, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{64, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{128, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE} \
}
#define NET_DIM_TX_CQE_PROFILES { \
{5, 128}, \
{8, 64}, \
{16, 32}, \
{32, 32}, \
{64, 32} \
}
static const struct dim_cq_moder
rx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
NET_DIM_RX_EQE_PROFILES,
NET_DIM_RX_CQE_PROFILES,
};
static const struct dim_cq_moder
tx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
NET_DIM_TX_EQE_PROFILES,
NET_DIM_TX_CQE_PROFILES,
};
/**
* 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);
#endif /* DIM_H */

273
include/linux/net_dim.h
View file

@ -1,273 +0,0 @@
/*
* 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>
#include <linux/dim.h>
#define NET_DIM_PARAMS_NUM_PROFILES 5
/* 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
#define NET_DIM_DEF_PROFILE_EQE 1
/* All profiles sizes must be NET_PARAMS_DIM_NUM_PROFILES */
#define NET_DIM_RX_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_RX_CQE_PROFILES { \
{2, 256}, \
{8, 128}, \
{16, 64}, \
{32, 64}, \
{64, 64} \
}
#define NET_DIM_TX_EQE_PROFILES { \
{1, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{8, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{32, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{64, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \
{128, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE} \
}
#define NET_DIM_TX_CQE_PROFILES { \
{5, 128}, \
{8, 64}, \
{16, 32}, \
{32, 32}, \
{64, 32} \
}
static const struct dim_cq_moder
rx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
NET_DIM_RX_EQE_PROFILES,
NET_DIM_RX_CQE_PROFILES,
};
static const struct dim_cq_moder
tx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
NET_DIM_TX_EQE_PROFILES,
NET_DIM_TX_CQE_PROFILES,
};
static inline struct dim_cq_moder
net_dim_get_rx_moderation(u8 cq_period_mode, int ix)
{
struct dim_cq_moder cq_moder = rx_profile[cq_period_mode][ix];
cq_moder.cq_period_mode = cq_period_mode;
return cq_moder;
}
static inline struct dim_cq_moder
net_dim_get_def_rx_moderation(u8 cq_period_mode)
{
u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
return net_dim_get_rx_moderation(cq_period_mode, profile_ix);
}
static inline struct dim_cq_moder
net_dim_get_tx_moderation(u8 cq_period_mode, int ix)
{
struct dim_cq_moder cq_moder = tx_profile[cq_period_mode][ix];
cq_moder.cq_period_mode = cq_period_mode;
return cq_moder;
}
static inline struct dim_cq_moder
net_dim_get_def_tx_moderation(u8 cq_period_mode)
{
u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
return net_dim_get_tx_moderation(cq_period_mode, profile_ix);
}
static inline int net_dim_step(struct dim *dim)
{
if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
return DIM_TOO_TIRED;
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
break;
case DIM_GOING_RIGHT:
if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1))
return DIM_ON_EDGE;
dim->profile_ix++;
dim->steps_right++;
break;
case DIM_GOING_LEFT:
if (dim->profile_ix == 0)
return DIM_ON_EDGE;
dim->profile_ix--;
dim->steps_left++;
break;
}
dim->tired++;
return DIM_STEPPED;
}
static inline void net_dim_exit_parking(struct dim *dim)
{
dim->tune_state = dim->profile_ix ? DIM_GOING_LEFT :
DIM_GOING_RIGHT;
net_dim_step(dim);
}
static inline int net_dim_stats_compare(struct dim_stats *curr,
struct dim_stats *prev)
{
if (!prev->bpms)
return curr->bpms ? DIM_STATS_BETTER :
DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms))
return (curr->bpms > prev->bpms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
if (!prev->ppms)
return curr->ppms ? DIM_STATS_BETTER :
DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms))
return (curr->ppms > prev->ppms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
if (!prev->epms)
return DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms))
return (curr->epms < prev->epms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
return DIM_STATS_SAME;
}
static inline bool net_dim_decision(struct dim_stats *curr_stats,
struct 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 DIM_PARKING_ON_TOP:
stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats);
if (stats_res != DIM_STATS_SAME)
net_dim_exit_parking(dim);
break;
case DIM_PARKING_TIRED:
dim->tired--;
if (!dim->tired)
net_dim_exit_parking(dim);
break;
case DIM_GOING_RIGHT:
case DIM_GOING_LEFT:
stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats);
if (stats_res != DIM_STATS_BETTER)
dim_turn(dim);
if (dim_on_top(dim)) {
dim_park_on_top(dim);
break;
}
step_res = net_dim_step(dim);
switch (step_res) {
case DIM_ON_EDGE:
dim_park_on_top(dim);
break;
case DIM_TOO_TIRED:
dim_park_tired(dim);
break;
}
break;
}
if (prev_state != DIM_PARKING_ON_TOP ||
dim->tune_state != DIM_PARKING_ON_TOP)
dim->prev_stats = *curr_stats;
return dim->profile_ix != prev_ix;
}
static inline void net_dim(struct dim *dim,
struct dim_sample end_sample)
{
struct dim_stats curr_stats;
u16 nevents;
switch (dim->state) {
case DIM_MEASURE_IN_PROGRESS:
nevents = BIT_GAP(BITS_PER_TYPE(u16),
end_sample.event_ctr,
dim->start_sample.event_ctr);
if (nevents < DIM_NEVENTS)
break;
dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats);
if (net_dim_decision(&curr_stats, dim)) {
dim->state = DIM_APPLY_NEW_PROFILE;
schedule_work(&dim->work);
break;
}
/* fall through */
case DIM_START_MEASURE:
dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr,
end_sample.byte_ctr, &dim->start_sample);
dim->state = DIM_MEASURE_IN_PROGRESS;
break;
case DIM_APPLY_NEW_PROFILE:
break;
}
}
#endif /* NET_DIM_H */

8
lib/Kconfig
View file

@ -562,6 +562,14 @@ config SIGNATURE
Digital signature verification. Currently only RSA is supported.
Implementation is done using GnuPG MPI library
config DIMLIB
bool "DIM library"
default y
help
Dynamic Interrupt Moderation library.
Implements an algorithm for dynamically change CQ modertion values
according to run time performance.
#
# libfdt files, only selected if needed.
#

1
lib/Makefile
View file

@ -202,6 +202,7 @@ obj-$(CONFIG_GLOB) += glob.o
obj-$(CONFIG_GLOB_SELFTEST) += globtest.o
obj-$(CONFIG_MPILIB) += mpi/
obj-$(CONFIG_DIMLIB) += dim/
obj-$(CONFIG_SIGNATURE) += digsig.o
lib-$(CONFIG_CLZ_TAB) += clz_tab.o

9
lib/dim/Makefile Normal file
View file

@ -0,0 +1,9 @@
#
# DIM Dynamic Interrupt Moderation library
#
obj-$(CONFIG_DIMLIB) = net_dim.o
net_dim-y = \
dim.o \
net_dim.o

74
lib/dim/dim.c Normal file
View file

@ -0,0 +1,74 @@
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
* Copyright (c) 2019, Mellanox Technologies inc. All rights reserved.
*/
#include <linux/dim.h>
bool dim_on_top(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
return true;
case DIM_GOING_RIGHT:
return (dim->steps_left > 1) && (dim->steps_right == 1);
default: /* DIM_GOING_LEFT */
return (dim->steps_right > 1) && (dim->steps_left == 1);
}
}
EXPORT_SYMBOL(dim_on_top);
void dim_turn(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
break;
case DIM_GOING_RIGHT:
dim->tune_state = DIM_GOING_LEFT;
dim->steps_left = 0;
break;
case DIM_GOING_LEFT:
dim->tune_state = DIM_GOING_RIGHT;
dim->steps_right = 0;
break;
}
}
EXPORT_SYMBOL(dim_turn);
void dim_park_on_top(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tired = 0;
dim->tune_state = DIM_PARKING_ON_TOP;
}
EXPORT_SYMBOL(dim_park_on_top);
void dim_park_tired(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tune_state = DIM_PARKING_TIRED;
}
EXPORT_SYMBOL(dim_park_tired);
void dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
struct 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(DIM_NEVENTS * USEC_PER_MSEC,
delta_us);
}
EXPORT_SYMBOL(dim_calc_stats);

190
lib/dim/net_dim.c Normal file
View file

@ -0,0 +1,190 @@
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
* Copyright (c) 2018, Mellanox Technologies inc. All rights reserved.
*/
#include <linux/dim.h>
struct dim_cq_moder
net_dim_get_rx_moderation(u8 cq_period_mode, int ix)
{
struct dim_cq_moder cq_moder = rx_profile[cq_period_mode][ix];
cq_moder.cq_period_mode = cq_period_mode;
return cq_moder;
}
EXPORT_SYMBOL(net_dim_get_rx_moderation);
struct dim_cq_moder
net_dim_get_def_rx_moderation(u8 cq_period_mode)
{
u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
return net_dim_get_rx_moderation(cq_period_mode, profile_ix);
}
EXPORT_SYMBOL(net_dim_get_def_rx_moderation);
struct dim_cq_moder
net_dim_get_tx_moderation(u8 cq_period_mode, int ix)
{
struct dim_cq_moder cq_moder = tx_profile[cq_period_mode][ix];
cq_moder.cq_period_mode = cq_period_mode;
return cq_moder;
}
EXPORT_SYMBOL(net_dim_get_tx_moderation);
struct dim_cq_moder
net_dim_get_def_tx_moderation(u8 cq_period_mode)
{
u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
return net_dim_get_tx_moderation(cq_period_mode, profile_ix);
}
EXPORT_SYMBOL(net_dim_get_def_tx_moderation);
static int net_dim_step(struct dim *dim)
{
if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
return DIM_TOO_TIRED;
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
break;
case DIM_GOING_RIGHT:
if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1))
return DIM_ON_EDGE;
dim->profile_ix++;
dim->steps_right++;
break;
case DIM_GOING_LEFT:
if (dim->profile_ix == 0)
return DIM_ON_EDGE;
dim->profile_ix--;
dim->steps_left++;
break;
}
dim->tired++;
return DIM_STEPPED;
}
static void net_dim_exit_parking(struct dim *dim)
{
dim->tune_state = dim->profile_ix ? DIM_GOING_LEFT : DIM_GOING_RIGHT;
net_dim_step(dim);
}
static int net_dim_stats_compare(struct dim_stats *curr,
struct dim_stats *prev)
{
if (!prev->bpms)
return curr->bpms ? DIM_STATS_BETTER : DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms))
return (curr->bpms > prev->bpms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
if (!prev->ppms)
return curr->ppms ? DIM_STATS_BETTER :
DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms))
return (curr->ppms > prev->ppms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
if (!prev->epms)
return DIM_STATS_SAME;
if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms))
return (curr->epms < prev->epms) ? DIM_STATS_BETTER :
DIM_STATS_WORSE;
return DIM_STATS_SAME;
}
static bool net_dim_decision(struct dim_stats *curr_stats, struct 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 DIM_PARKING_ON_TOP:
stats_res = net_dim_stats_compare(curr_stats,
&dim->prev_stats);
if (stats_res != DIM_STATS_SAME)
net_dim_exit_parking(dim);
break;
case DIM_PARKING_TIRED:
dim->tired--;
if (!dim->tired)
net_dim_exit_parking(dim);
break;
case DIM_GOING_RIGHT:
case DIM_GOING_LEFT:
stats_res = net_dim_stats_compare(curr_stats,
&dim->prev_stats);
if (stats_res != DIM_STATS_BETTER)
dim_turn(dim);
if (dim_on_top(dim)) {
dim_park_on_top(dim);
break;
}
step_res = net_dim_step(dim);
switch (step_res) {
case DIM_ON_EDGE:
dim_park_on_top(dim);
break;
case DIM_TOO_TIRED:
dim_park_tired(dim);
break;
}
break;
}
if (prev_state != DIM_PARKING_ON_TOP ||
dim->tune_state != DIM_PARKING_ON_TOP)
dim->prev_stats = *curr_stats;
return dim->profile_ix != prev_ix;
}
void net_dim(struct dim *dim, struct dim_sample end_sample)
{
struct dim_stats curr_stats;
u16 nevents;
switch (dim->state) {
case DIM_MEASURE_IN_PROGRESS:
nevents = BIT_GAP(BITS_PER_TYPE(u16),
end_sample.event_ctr,
dim->start_sample.event_ctr);
if (nevents < DIM_NEVENTS)
break;
dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats);
if (net_dim_decision(&curr_stats, dim)) {
dim->state = DIM_APPLY_NEW_PROFILE;
schedule_work(&dim->work);
break;
}
/* fall through */
case DIM_START_MEASURE:
dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr,
end_sample.byte_ctr, &dim->start_sample);
dim->state = DIM_MEASURE_IN_PROGRESS;
break;
case DIM_APPLY_NEW_PROFILE:
break;
}
}
EXPORT_SYMBOL(net_dim);