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Merge branch 'ewma'

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Johannes Berg says:

====================
average: convert users to inline implementation

Since there's very little benefit of the out-of-line implementation
(a single byte of .text in one driver as far as I've seen), convert
all drivers to the inline implementation, saving memory, and remove
the out-of-line implementation.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-08-20 14:10:23 -07:00
commit 84b6714e54
13 changed files with 29 additions and 132 deletions
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1
drivers/net/Kconfig
View File

@ -282,7 +282,6 @@ config VETH
config VIRTIO_NET
tristate "Virtio network driver"
depends on VIRTIO
select AVERAGE
---help---
This is the virtual network driver for virtio. It can be used with
lguest or QEMU based VMMs (like KVM or Xen). Say Y or M.

22
drivers/net/virtio_net.c
View File

@ -40,12 +40,12 @@ module_param(gso, bool, 0444);
#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128
/* Weight used for the RX packet size EWMA. The average packet size is used to
* determine the packet buffer size when refilling RX rings. As the entire RX
* ring may be refilled at once, the weight is chosen so that the EWMA will be
* insensitive to short-term, transient changes in packet size.
/* RX packet size EWMA. The average packet size is used to determine the packet
* buffer size when refilling RX rings. As the entire RX ring may be refilled
* at once, the weight is chosen so that the EWMA will be insensitive to short-
* term, transient changes in packet size.
*/
#define RECEIVE_AVG_WEIGHT 64
DECLARE_EWMA(pkt_len, 1, 64)
/* Minimum alignment for mergeable packet buffers. */
#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
@ -85,7 +85,7 @@ struct receive_queue {
struct page *pages;
/* Average packet length for mergeable receive buffers. */
struct ewma mrg_avg_pkt_len;
struct ewma_pkt_len mrg_avg_pkt_len;
/* Page frag for packet buffer allocation. */
struct page_frag alloc_frag;
@ -407,7 +407,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
}
}
ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
return head_skb;
err_skb:
@ -600,12 +600,12 @@ static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
return err;
}
static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
{
const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
unsigned int len;
len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
}
@ -1615,7 +1615,7 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
napi_hash_add(&vi->rq[i].napi);
sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
}
@ -1658,7 +1658,7 @@ static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
{
struct virtnet_info *vi = netdev_priv(queue->dev);
unsigned int queue_index = get_netdev_rx_queue_index(queue);
struct ewma *avg;
struct ewma_pkt_len *avg;
BUG_ON(queue_index >= vi->max_queue_pairs);
avg = &vi->rq[queue_index].mrg_avg_pkt_len;

1
drivers/net/wireless/ath/ath5k/Kconfig
View File

@ -5,7 +5,6 @@ config ATH5K
select MAC80211_LEDS
select LEDS_CLASS
select NEW_LEDS
select AVERAGE
select ATH5K_AHB if ATH25
select ATH5K_PCI if !ATH25
---help---

4
drivers/net/wireless/ath/ath5k/ani.c
View File

@ -223,7 +223,7 @@ static void
ath5k_ani_raise_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as,
bool ofdm_trigger)
{
int rssi = ewma_read(&ah->ah_beacon_rssi_avg);
int rssi = ewma_beacon_rssi_read(&ah->ah_beacon_rssi_avg);
ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "raise immunity (%s)",
ofdm_trigger ? "ODFM" : "CCK");
@ -309,7 +309,7 @@ ath5k_ani_raise_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as,
static void
ath5k_ani_lower_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as)
{
int rssi = ewma_read(&ah->ah_beacon_rssi_avg);
int rssi = ewma_beacon_rssi_read(&ah->ah_beacon_rssi_avg);
ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "lower immunity");

4
drivers/net/wireless/ath/ath5k/ath5k.h
View File

@ -1252,6 +1252,8 @@ struct ath5k_statistics {
#define ATH5K_TXQ_LEN_MAX (ATH_TXBUF / 4) /* bufs per queue */
#define ATH5K_TXQ_LEN_LOW (ATH5K_TXQ_LEN_MAX / 2) /* low mark */
DECLARE_EWMA(beacon_rssi, 1024, 8)
/* Driver state associated with an instance of a device */
struct ath5k_hw {
struct ath_common common;
@ -1432,7 +1434,7 @@ struct ath5k_hw {
struct ath5k_nfcal_hist ah_nfcal_hist;
/* average beacon RSSI in our BSS (used by ANI) */
struct ewma ah_beacon_rssi_avg;
struct ewma_beacon_rssi ah_beacon_rssi_avg;
/* noise floor from last periodic calibration */
s32 ah_noise_floor;

4
drivers/net/wireless/ath/ath5k/base.c
View File

@ -1430,7 +1430,7 @@ ath5k_receive_frame(struct ath5k_hw *ah, struct sk_buff *skb,
trace_ath5k_rx(ah, skb);
if (ath_is_mybeacon(common, (struct ieee80211_hdr *)skb->data)) {
ewma_add(&ah->ah_beacon_rssi_avg, rs->rs_rssi);
ewma_beacon_rssi_add(&ah->ah_beacon_rssi_avg, rs->rs_rssi);
/* check beacons in IBSS mode */
if (ah->opmode == NL80211_IFTYPE_ADHOC)
@ -2936,7 +2936,7 @@ ath5k_reset(struct ath5k_hw *ah, struct ieee80211_channel *chan,
ah->ah_cal_next_short = jiffies +
msecs_to_jiffies(ATH5K_TUNE_CALIBRATION_INTERVAL_SHORT);
ewma_init(&ah->ah_beacon_rssi_avg, 1024, 8);
ewma_beacon_rssi_init(&ah->ah_beacon_rssi_avg);
/* clear survey data and cycle counters */
memset(&ah->survey, 0, sizeof(ah->survey));

2
drivers/net/wireless/ath/ath5k/debug.c
View File

@ -722,7 +722,7 @@ static ssize_t read_file_ani(struct file *file, char __user *user_buf,
st->mib_intr);
len += snprintf(buf + len, sizeof(buf) - len,
"beacon RSSI average:\t%d\n",
(int)ewma_read(&ah->ah_beacon_rssi_avg));
(int)ewma_beacon_rssi_read(&ah->ah_beacon_rssi_avg));
#define CC_PRINT(_struct, _field) \
_struct._field, \

1
drivers/net/wireless/rt2x00/Kconfig
View File

@ -240,7 +240,6 @@ config RT2X00_LIB_USB
config RT2X00_LIB
tristate
select AVERAGE
config RT2X00_LIB_FIRMWARE
bool

6
drivers/net/wireless/rt2x00/rt2x00.h
View File

@ -254,6 +254,8 @@ struct link_qual {
int tx_failed;
};
DECLARE_EWMA(rssi, 1024, 8)
/*
* Antenna settings about the currently active link.
*/
@ -285,7 +287,7 @@ struct link_ant {
* Similar to the avg_rssi in the link_qual structure
* this value is updated by using the walking average.
*/
struct ewma rssi_ant;
struct ewma_rssi rssi_ant;
};
/*
@ -314,7 +316,7 @@ struct link {
/*
* Currently active average RSSI value
*/
struct ewma avg_rssi;
struct ewma_rssi avg_rssi;
/*
* Work structure for scheduling periodic link tuning.

18
drivers/net/wireless/rt2x00/rt2x00link.c
View File

@ -33,15 +33,11 @@
*/
#define DEFAULT_RSSI -128
/* Constants for EWMA calculations. */
#define RT2X00_EWMA_FACTOR 1024
#define RT2X00_EWMA_WEIGHT 8
static inline int rt2x00link_get_avg_rssi(struct ewma *ewma)
static inline int rt2x00link_get_avg_rssi(struct ewma_rssi *ewma)
{
unsigned long avg;
avg = ewma_read(ewma);
avg = ewma_rssi_read(ewma);
if (avg)
return -avg;
@ -76,8 +72,7 @@ static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
{
ewma_init(&rt2x00dev->link.ant.rssi_ant, RT2X00_EWMA_FACTOR,
RT2X00_EWMA_WEIGHT);
ewma_rssi_init(&rt2x00dev->link.ant.rssi_ant);
}
static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
@ -225,12 +220,12 @@ void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
/*
* Update global RSSI
*/
ewma_add(&link->avg_rssi, -rxdesc->rssi);
ewma_rssi_add(&link->avg_rssi, -rxdesc->rssi);
/*
* Update antenna RSSI
*/
ewma_add(&ant->rssi_ant, -rxdesc->rssi);
ewma_rssi_add(&ant->rssi_ant, -rxdesc->rssi);
}
void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
@ -285,8 +280,7 @@ void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
*/
rt2x00dev->link.count = 0;
memset(qual, 0, sizeof(*qual));
ewma_init(&rt2x00dev->link.avg_rssi, RT2X00_EWMA_FACTOR,
RT2X00_EWMA_WEIGHT);
ewma_rssi_init(&rt2x00dev->link.avg_rssi);
/*
* Restore the VGC level as stored in the registers,

24
include/linux/average.h
View File

@ -3,30 +3,6 @@
/* Exponentially weighted moving average (EWMA) */
/* For more documentation see lib/average.c */
struct ewma {
unsigned long internal;
unsigned long factor;
unsigned long weight;
};
extern void ewma_init(struct ewma *avg, unsigned long factor,
unsigned long weight);
extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
/**
* ewma_read() - Get average value
* @avg: Average structure
*
* Returns the average value held in @avg.
*/
static inline unsigned long ewma_read(const struct ewma *avg)
{
return avg->internal >> avg->factor;
}
#define DECLARE_EWMA(name, _factor, _weight) \
struct ewma_##name { \
unsigned long internal; \

10
lib/Kconfig
View File

@ -460,16 +460,6 @@ config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
config LRU_CACHE
tristate
config AVERAGE
bool "Averaging functions"
help
This option is provided for the case where no in-kernel-tree
modules require averaging functions, but a module built outside
the kernel tree does. Such modules that use library averaging
functions require Y here.
If unsure, say N.
config CLZ_TAB
bool

64
lib/average.c
View File

@ -1,64 +0,0 @@
/*
* lib/average.c
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/export.h>
#include <linux/average.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/log2.h>
/**
* DOC: Exponentially Weighted Moving Average (EWMA)
*
* These are generic functions for calculating Exponentially Weighted Moving
* Averages (EWMA). We keep a structure with the EWMA parameters and a scaled
* up internal representation of the average value to prevent rounding errors.
* The factor for scaling up and the exponential weight (or decay rate) have to
* be specified thru the init fuction. The structure should not be accessed
* directly but only thru the helper functions.
*/
/**
* ewma_init() - Initialize EWMA parameters
* @avg: Average structure
* @factor: Factor to use for the scaled up internal value. The maximum value
* of averages can be ULONG_MAX/(factor*weight). For performance reasons
* factor has to be a power of 2.
* @weight: Exponential weight, or decay rate. This defines how fast the
* influence of older values decreases. For performance reasons weight has
* to be a power of 2.
*
* Initialize the EWMA parameters for a given struct ewma @avg.
*/
void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)
{
WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));
avg->weight = ilog2(weight);
avg->factor = ilog2(factor);
avg->internal = 0;
}
EXPORT_SYMBOL(ewma_init);
/**
* ewma_add() - Exponentially weighted moving average (EWMA)
* @avg: Average structure
* @val: Current value
*
* Add a sample to the average.
*/
struct ewma *ewma_add(struct ewma *avg, unsigned long val)
{
unsigned long internal = ACCESS_ONCE(avg->internal);
ACCESS_ONCE(avg->internal) = internal ?
(((internal << avg->weight) - internal) +
(val << avg->factor)) >> avg->weight :
(val << avg->factor);
return avg;
}
EXPORT_SYMBOL(ewma_add);