From c1ebcdb8c422cd73f54bcd2b9953e443a47667e5 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 23 Jun 2005 20:08:59 -0700 Subject: [NET]: Remove obsolete fastroute stats. Remove last vestiages of fastroute code that is no longer used. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/core/dev.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index ab935778ce81..4f1ae2efe872 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2056,14 +2056,8 @@ static int softnet_seq_show(struct seq_file *seq, void *v) seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n", s->total, s->dropped, s->time_squeeze, s->throttled, - s->fastroute_hit, s->fastroute_success, s->fastroute_defer, - s->fastroute_deferred_out, -#if 0 - s->fastroute_latency_reduction -#else - s->cpu_collision -#endif - ); + 0, 0, 0, 0, /* was fastroute */ + s->cpu_collision ); return 0; } -- cgit v1.2.3 From 34008d8c631d067caffa136313260525f3ae48a2 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 23 Jun 2005 20:10:00 -0700 Subject: [NET]: Remove obsolete netif_rx congestion sensing mechanism. 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 Signed-off-by: David S. Miller --- net/core/dev.c | 88 +--------------------------------------------------------- 1 file changed, 1 insertion(+), 87 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 4f1ae2efe872..3156df699f01 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -115,18 +115,6 @@ #endif /* CONFIG_NET_RADIO */ #include -/* 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 @@ out: 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); -- cgit v1.2.3 From 31aa02c53c84658f6694f319f09e232ede27be5a Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 23 Jun 2005 20:12:48 -0700 Subject: [NET]: Eliminate netif_rx massive packet drops. Eliminate the throttling behaviour when the netif receive queue fills because it behaves badly when using high speed networks under load. The throttling cause multiple packet drops that cause TCP to go into slow start mode. The same effective patch has been part of BIC TCP and H-TCP as well as part of Web100. The existing code drops 100's of packets when the queue fills; this changes it to individual packet drop-tail. Signed-off-by: Stephen Hemmminger Signed-off-by: David S. Miller --- net/core/dev.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 3156df699f01..1a64508e527f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -198,7 +198,7 @@ static struct notifier_block *netdev_chain; * Device drivers call our routines to queue packets here. We empty the * queue in the local softnet handler. */ -DEFINE_PER_CPU(struct softnet_data, softnet_data) = { 0, }; +DEFINE_PER_CPU(struct softnet_data, softnet_data) = { NULL }; #ifdef CONFIG_SYSFS extern int netdev_sysfs_init(void); @@ -1372,7 +1372,6 @@ DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, }; int netif_rx(struct sk_buff *skb) { - int this_cpu; struct softnet_data *queue; unsigned long flags; @@ -1388,15 +1387,11 @@ int netif_rx(struct sk_buff *skb) * short when CPU is congested, but is still operating. */ local_irq_save(flags); - this_cpu = smp_processor_id(); queue = &__get_cpu_var(softnet_data); __get_cpu_var(netdev_rx_stat).total++; if (queue->input_pkt_queue.qlen <= netdev_max_backlog) { if (queue->input_pkt_queue.qlen) { - if (queue->throttle) - goto drop; - enqueue: dev_hold(skb->dev); __skb_queue_tail(&queue->input_pkt_queue, skb); @@ -1404,19 +1399,10 @@ enqueue: return NET_RX_SUCCESS; } - if (queue->throttle) - queue->throttle = 0; - netif_rx_schedule(&queue->backlog_dev); goto enqueue; } - if (!queue->throttle) { - queue->throttle = 1; - __get_cpu_var(netdev_rx_stat).throttled++; - } - -drop: __get_cpu_var(netdev_rx_stat).dropped++; local_irq_restore(flags); @@ -1701,8 +1687,6 @@ job_done: smp_mb__before_clear_bit(); netif_poll_enable(backlog_dev); - if (queue->throttle) - queue->throttle = 0; local_irq_enable(); return 0; } @@ -1976,7 +1960,7 @@ static int softnet_seq_show(struct seq_file *seq, void *v) struct netif_rx_stats *s = v; seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n", - s->total, s->dropped, s->time_squeeze, s->throttled, + s->total, s->dropped, s->time_squeeze, 0, 0, 0, 0, 0, /* was fastroute */ s->cpu_collision ); return 0; @@ -3220,7 +3204,6 @@ 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->completion_queue = NULL; INIT_LIST_HEAD(&queue->poll_list); set_bit(__LINK_STATE_START, &queue->backlog_dev.state); -- cgit v1.2.3 From 51b0bdedb8e784d0d969a6b77151911130812400 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 23 Jun 2005 20:14:40 -0700 Subject: [NET]: Separate two usages of netdev_max_backlog. Separate out the two uses of netdev_max_backlog. One controls the upper bound on packets processed per softirq, the new name for this is netdev_budget; the other controls the limit on packets queued via netif_rx. Increase the max_backlog default to account for faster processors. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/core/dev.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 1a64508e527f..7016e0c36b3d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1346,7 +1346,8 @@ out: Receiver routines =======================================================================*/ -int netdev_max_backlog = 300; +int netdev_max_backlog = 1000; +int netdev_budget = 300; int weight_p = 64; /* old backlog weight */ DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, }; @@ -1695,8 +1696,7 @@ static void net_rx_action(struct softirq_action *h) { struct softnet_data *queue = &__get_cpu_var(softnet_data); unsigned long start_time = jiffies; - int budget = netdev_max_backlog; - + int budget = netdev_budget; local_irq_disable(); -- cgit v1.2.3