Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

[NET]: Remove obsolete netif_rx congestion sensing mechanism.

Browse source 
Remove the congestion sensing mechanism from netif_rx, and always
return either full or empty.  Almost no driver checks the return value
from netif_rx, and those that do only use it for debug messages.

The original design of netif_rx was to do flow control based on the
receive queue, but NAPI has supplanted this and no driver uses the
feedback.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2005-06-23 20:10:00 -07:00 committed by David S. Miller
parent c1ebcdb8c4
commit 34008d8c63
3 changed files with 1 additions and 125 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/netdevice.h
View file

@ -558,8 +558,6 @@ static inline int unregister_gifconf(unsigned int family)
struct softnet_data
{
int throttle;
int cng_level;
int avg_blog;
struct sk_buff_head input_pkt_queue;
struct list_head poll_list;
struct net_device *output_queue;

88
net/core/dev.c
View file

@ -115,18 +115,6 @@
#endif /* CONFIG_NET_RADIO */
#include <asm/current.h>
/* This define, if set, will randomly drop a packet when congestion
* is more than moderate. It helps fairness in the multi-interface
* case when one of them is a hog, but it kills performance for the
* single interface case so it is off now by default.
*/
#undef RAND_LIE
/* Setting this will sample the queue lengths and thus congestion
* via a timer instead of as each packet is received.
*/
#undef OFFLINE_SAMPLE
/*
* The list of packet types we will receive (as opposed to discard)
* and the routines to invoke.
@ -159,11 +147,6 @@ static DEFINE_SPINLOCK(ptype_lock);
static struct list_head ptype_base[16]; /* 16 way hashed list */
static struct list_head ptype_all; /* Taps */
#ifdef OFFLINE_SAMPLE
static void sample_queue(unsigned long dummy);
static struct timer_list samp_timer = TIMER_INITIALIZER(sample_queue, 0, 0);
#endif
/*
* The @dev_base list is protected by @dev_base_lock and the rtln
* semaphore.
@ -1365,69 +1348,10 @@ int dev_queue_xmit(struct sk_buff *skb)
int netdev_max_backlog = 300;
int weight_p = 64; /* old backlog weight */
/* These numbers are selected based on intuition and some
* experimentatiom, if you have more scientific way of doing this
* please go ahead and fix things.
*/
int no_cong_thresh = 10;
int no_cong = 20;
int lo_cong = 100;
int mod_cong = 290;
DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
static void get_sample_stats(int cpu)
{
#ifdef RAND_LIE
unsigned long rd;
int rq;
#endif
struct softnet_data *sd = &per_cpu(softnet_data, cpu);
int blog = sd->input_pkt_queue.qlen;
int avg_blog = sd->avg_blog;
avg_blog = (avg_blog >> 1) + (blog >> 1);
if (avg_blog > mod_cong) {
/* Above moderate congestion levels. */
sd->cng_level = NET_RX_CN_HIGH;
#ifdef RAND_LIE
rd = net_random();
rq = rd % netdev_max_backlog;
if (rq < avg_blog) /* unlucky bastard */
sd->cng_level = NET_RX_DROP;
#endif
} else if (avg_blog > lo_cong) {
sd->cng_level = NET_RX_CN_MOD;
#ifdef RAND_LIE
rd = net_random();
rq = rd % netdev_max_backlog;
if (rq < avg_blog) /* unlucky bastard */
sd->cng_level = NET_RX_CN_HIGH;
#endif
} else if (avg_blog > no_cong)
sd->cng_level = NET_RX_CN_LOW;
else /* no congestion */
sd->cng_level = NET_RX_SUCCESS;
sd->avg_blog = avg_blog;
}
#ifdef OFFLINE_SAMPLE
static void sample_queue(unsigned long dummy)
{
/* 10 ms 0r 1ms -- i don't care -- JHS */
int next_tick = 1;
int cpu = smp_processor_id();
get_sample_stats(cpu);
next_tick += jiffies;
mod_timer(&samp_timer, next_tick);
}
#endif
/**
* netif_rx - post buffer to the network code
* @skb: buffer to post
@ -1476,11 +1400,8 @@ int netif_rx(struct sk_buff *skb)
enqueue:
dev_hold(skb->dev);
__skb_queue_tail(&queue->input_pkt_queue, skb);
#ifndef OFFLINE_SAMPLE
get_sample_stats(this_cpu);
#endif
local_irq_restore(flags);
return queue->cng_level;
return NET_RX_SUCCESS;
}
if (queue->throttle)
@ -3300,8 +3221,6 @@ static int __init net_dev_init(void)
queue = &per_cpu(softnet_data, i);
skb_queue_head_init(&queue->input_pkt_queue);
queue->throttle = 0;
queue->cng_level = 0;
queue->avg_blog = 10; /* arbitrary non-zero */
queue->completion_queue = NULL;
INIT_LIST_HEAD(&queue->poll_list);
set_bit(__LINK_STATE_START, &queue->backlog_dev.state);
@ -3310,11 +3229,6 @@ static int __init net_dev_init(void)
atomic_set(&queue->backlog_dev.refcnt, 1);
}
#ifdef OFFLINE_SAMPLE
samp_timer.expires = jiffies + (10 * HZ);
add_timer(&samp_timer);
#endif
dev_boot_phase = 0;
open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);

36
net/core/sysctl_net_core.c
View file

@ -14,10 +14,6 @@
extern int netdev_max_backlog;
extern int weight_p;
extern int no_cong_thresh;
extern int no_cong;
extern int lo_cong;
extern int mod_cong;
extern int net_msg_cost;
extern int net_msg_burst;
@ -84,38 +80,6 @@ ctl_table core_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_NO_CONG_THRESH,
.procname = "no_cong_thresh",
.data = &no_cong_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_NO_CONG,
.procname = "no_cong",
.data = &no_cong,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_LO_CONG,
.procname = "lo_cong",
.data = &lo_cong,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_MOD_CONG,
.procname = "mod_cong",
.data = &mod_cong,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_MSG_COST,
.procname = "message_cost",