neigh: new unresolved queue limits

Le mercredi 09 novembre 2011 à 16:21 -0500, David Miller a écrit :
> From: David Miller <davem@davemloft.net>
> Date: Wed, 09 Nov 2011 16:16:44 -0500 (EST)
>
> > From: Eric Dumazet <eric.dumazet@gmail.com>
> > Date: Wed, 09 Nov 2011 12:14:09 +0100
> >
> >> unres_qlen is the number of frames we are able to queue per unresolved
> >> neighbour. Its default value (3) was never changed and is responsible
> >> for strange drops, especially if IP fragments are used, or multiple
> >> sessions start in parallel. Even a single tcp flow can hit this limit.
> >  ...
> >
> > Ok, I've applied this, let's see what happens :-)
>
> Early answer, build fails.
>
> Please test build this patch with DECNET enabled and resubmit.  The
> decnet neigh layer still refers to the removed ->queue_len member.
>
> Thanks.

Ouch, this was fixed on one machine yesterday, but not the other one I
used this morning, sorry.

[PATCH V5 net-next] neigh: new unresolved queue limits

unres_qlen is the number of frames we are able to queue per unresolved
neighbour. Its default value (3) was never changed and is responsible
for strange drops, especially if IP fragments are used, or multiple
sessions start in parallel. Even a single tcp flow can hit this limit.

$ arp -d 192.168.20.108 ; ping -c 2 -s 8000 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 8000(8028) bytes of data.
8008 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.322 ms

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2011-11-09 12:07:14 +00:00 committed by David S. Miller
parent 292d139898
commit 8b5c171bb3
8 changed files with 128 additions and 56 deletions

View file

@ -31,6 +31,16 @@ neigh/default/gc_thresh3 - INTEGER
when using large numbers of interfaces and when communicating
with large numbers of directly-connected peers.
neigh/default/unres_qlen_bytes - INTEGER
The maximum number of bytes which may be used by packets
queued for each unresolved address by other network layers.
(added in linux 3.3)
neigh/default/unres_qlen - INTEGER
The maximum number of packets which may be queued for each
unresolved address by other network layers.
(deprecated in linux 3.3) : use unres_qlen_bytes instead.
mtu_expires - INTEGER
Time, in seconds, that cached PMTU information is kept.

View file

@ -116,6 +116,7 @@ enum {
NDTPA_PROXY_DELAY, /* u64, msecs */
NDTPA_PROXY_QLEN, /* u32 */
NDTPA_LOCKTIME, /* u64, msecs */
NDTPA_QUEUE_LENBYTES, /* u32 */
__NDTPA_MAX
};
#define NDTPA_MAX (__NDTPA_MAX - 1)

View file

@ -59,7 +59,7 @@ struct neigh_parms {
int reachable_time;
int delay_probe_time;
int queue_len;
int queue_len_bytes;
int ucast_probes;
int app_probes;
int mcast_probes;
@ -99,6 +99,7 @@ struct neighbour {
rwlock_t lock;
atomic_t refcnt;
struct sk_buff_head arp_queue;
unsigned int arp_queue_len_bytes;
struct timer_list timer;
unsigned long used;
atomic_t probes;

View file

@ -329,7 +329,7 @@ static struct neigh_table clip_tbl = {
.gc_staletime = 60 * HZ,
.reachable_time = 30 * HZ,
.delay_probe_time = 5 * HZ,
.queue_len = 3,
.queue_len_bytes = 64 * 1024,
.ucast_probes = 3,
.mcast_probes = 3,
.anycast_delay = 1 * HZ,

View file

@ -238,6 +238,7 @@ static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
it to safe state.
*/
skb_queue_purge(&n->arp_queue);
n->arp_queue_len_bytes = 0;
n->output = neigh_blackhole;
if (n->nud_state & NUD_VALID)
n->nud_state = NUD_NOARP;
@ -702,6 +703,7 @@ void neigh_destroy(struct neighbour *neigh)
printk(KERN_WARNING "Impossible event.\n");
skb_queue_purge(&neigh->arp_queue);
neigh->arp_queue_len_bytes = 0;
dev_put(neigh->dev);
neigh_parms_put(neigh->parms);
@ -842,6 +844,7 @@ static void neigh_invalidate(struct neighbour *neigh)
write_lock(&neigh->lock);
}
skb_queue_purge(&neigh->arp_queue);
neigh->arp_queue_len_bytes = 0;
}
static void neigh_probe(struct neighbour *neigh)
@ -980,15 +983,20 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
if (neigh->nud_state == NUD_INCOMPLETE) {
if (skb) {
if (skb_queue_len(&neigh->arp_queue) >=
neigh->parms->queue_len) {
while (neigh->arp_queue_len_bytes + skb->truesize >
neigh->parms->queue_len_bytes) {
struct sk_buff *buff;
buff = __skb_dequeue(&neigh->arp_queue);
if (!buff)
break;
neigh->arp_queue_len_bytes -= buff->truesize;
kfree_skb(buff);
NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
}
skb_dst_force(skb);
__skb_queue_tail(&neigh->arp_queue, skb);
neigh->arp_queue_len_bytes += skb->truesize;
}
rc = 1;
}
@ -1175,6 +1183,7 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
write_lock_bh(&neigh->lock);
}
skb_queue_purge(&neigh->arp_queue);
neigh->arp_queue_len_bytes = 0;
}
out:
if (update_isrouter) {
@ -1747,7 +1756,11 @@ static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
NLA_PUT_U32(skb, NDTPA_IFINDEX, parms->dev->ifindex);
NLA_PUT_U32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt));
NLA_PUT_U32(skb, NDTPA_QUEUE_LEN, parms->queue_len);
NLA_PUT_U32(skb, NDTPA_QUEUE_LENBYTES, parms->queue_len_bytes);
/* approximative value for deprecated QUEUE_LEN (in packets) */
NLA_PUT_U32(skb, NDTPA_QUEUE_LEN,
DIV_ROUND_UP(parms->queue_len_bytes,
SKB_TRUESIZE(ETH_FRAME_LEN)));
NLA_PUT_U32(skb, NDTPA_PROXY_QLEN, parms->proxy_qlen);
NLA_PUT_U32(skb, NDTPA_APP_PROBES, parms->app_probes);
NLA_PUT_U32(skb, NDTPA_UCAST_PROBES, parms->ucast_probes);
@ -1974,7 +1987,11 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
switch (i) {
case NDTPA_QUEUE_LEN:
p->queue_len = nla_get_u32(tbp[i]);
p->queue_len_bytes = nla_get_u32(tbp[i]) *
SKB_TRUESIZE(ETH_FRAME_LEN);
break;
case NDTPA_QUEUE_LENBYTES:
p->queue_len_bytes = nla_get_u32(tbp[i]);
break;
case NDTPA_PROXY_QLEN:
p->proxy_qlen = nla_get_u32(tbp[i]);
@ -2635,117 +2652,158 @@ EXPORT_SYMBOL(neigh_app_ns);
#ifdef CONFIG_SYSCTL
#define NEIGH_VARS_MAX 19
static int proc_unres_qlen(ctl_table *ctl, int write, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
int size, ret;
ctl_table tmp = *ctl;
tmp.data = &size;
size = DIV_ROUND_UP(*(int *)ctl->data, SKB_TRUESIZE(ETH_FRAME_LEN));
ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
if (write && !ret)
*(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
return ret;
}
enum {
NEIGH_VAR_MCAST_PROBE,
NEIGH_VAR_UCAST_PROBE,
NEIGH_VAR_APP_PROBE,
NEIGH_VAR_RETRANS_TIME,
NEIGH_VAR_BASE_REACHABLE_TIME,
NEIGH_VAR_DELAY_PROBE_TIME,
NEIGH_VAR_GC_STALETIME,
NEIGH_VAR_QUEUE_LEN,
NEIGH_VAR_QUEUE_LEN_BYTES,
NEIGH_VAR_PROXY_QLEN,
NEIGH_VAR_ANYCAST_DELAY,
NEIGH_VAR_PROXY_DELAY,
NEIGH_VAR_LOCKTIME,
NEIGH_VAR_RETRANS_TIME_MS,
NEIGH_VAR_BASE_REACHABLE_TIME_MS,
NEIGH_VAR_GC_INTERVAL,
NEIGH_VAR_GC_THRESH1,
NEIGH_VAR_GC_THRESH2,
NEIGH_VAR_GC_THRESH3,
NEIGH_VAR_MAX
};
static struct neigh_sysctl_table {
struct ctl_table_header *sysctl_header;
struct ctl_table neigh_vars[NEIGH_VARS_MAX];
struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
char *dev_name;
} neigh_sysctl_template __read_mostly = {
.neigh_vars = {
{
[NEIGH_VAR_MCAST_PROBE] = {
.procname = "mcast_solicit",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_UCAST_PROBE] = {
.procname = "ucast_solicit",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_APP_PROBE] = {
.procname = "app_solicit",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_RETRANS_TIME] = {
.procname = "retrans_time",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_userhz_jiffies,
},
{
[NEIGH_VAR_BASE_REACHABLE_TIME] = {
.procname = "base_reachable_time",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
[NEIGH_VAR_DELAY_PROBE_TIME] = {
.procname = "delay_first_probe_time",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
[NEIGH_VAR_GC_STALETIME] = {
.procname = "gc_stale_time",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
[NEIGH_VAR_QUEUE_LEN] = {
.procname = "unres_qlen",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_unres_qlen,
},
[NEIGH_VAR_QUEUE_LEN_BYTES] = {
.procname = "unres_qlen_bytes",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_PROXY_QLEN] = {
.procname = "proxy_qlen",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_ANYCAST_DELAY] = {
.procname = "anycast_delay",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_userhz_jiffies,
},
{
[NEIGH_VAR_PROXY_DELAY] = {
.procname = "proxy_delay",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_userhz_jiffies,
},
{
[NEIGH_VAR_LOCKTIME] = {
.procname = "locktime",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_userhz_jiffies,
},
{
[NEIGH_VAR_RETRANS_TIME_MS] = {
.procname = "retrans_time_ms",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
{
[NEIGH_VAR_BASE_REACHABLE_TIME_MS] = {
.procname = "base_reachable_time_ms",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
{
[NEIGH_VAR_GC_INTERVAL] = {
.procname = "gc_interval",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
[NEIGH_VAR_GC_THRESH1] = {
.procname = "gc_thresh1",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_GC_THRESH2] = {
.procname = "gc_thresh2",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
[NEIGH_VAR_GC_THRESH3] = {
.procname = "gc_thresh3",
.maxlen = sizeof(int),
.mode = 0644,
@ -2778,47 +2836,49 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
if (!t)
goto err;
t->neigh_vars[0].data = &p->mcast_probes;
t->neigh_vars[1].data = &p->ucast_probes;
t->neigh_vars[2].data = &p->app_probes;
t->neigh_vars[3].data = &p->retrans_time;
t->neigh_vars[4].data = &p->base_reachable_time;
t->neigh_vars[5].data = &p->delay_probe_time;
t->neigh_vars[6].data = &p->gc_staletime;
t->neigh_vars[7].data = &p->queue_len;
t->neigh_vars[8].data = &p->proxy_qlen;
t->neigh_vars[9].data = &p->anycast_delay;
t->neigh_vars[10].data = &p->proxy_delay;
t->neigh_vars[11].data = &p->locktime;
t->neigh_vars[12].data = &p->retrans_time;
t->neigh_vars[13].data = &p->base_reachable_time;
t->neigh_vars[NEIGH_VAR_MCAST_PROBE].data = &p->mcast_probes;
t->neigh_vars[NEIGH_VAR_UCAST_PROBE].data = &p->ucast_probes;
t->neigh_vars[NEIGH_VAR_APP_PROBE].data = &p->app_probes;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME].data = &p->retrans_time;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].data = &p->base_reachable_time;
t->neigh_vars[NEIGH_VAR_DELAY_PROBE_TIME].data = &p->delay_probe_time;
t->neigh_vars[NEIGH_VAR_GC_STALETIME].data = &p->gc_staletime;
t->neigh_vars[NEIGH_VAR_QUEUE_LEN].data = &p->queue_len_bytes;
t->neigh_vars[NEIGH_VAR_QUEUE_LEN_BYTES].data = &p->queue_len_bytes;
t->neigh_vars[NEIGH_VAR_PROXY_QLEN].data = &p->proxy_qlen;
t->neigh_vars[NEIGH_VAR_ANYCAST_DELAY].data = &p->anycast_delay;
t->neigh_vars[NEIGH_VAR_PROXY_DELAY].data = &p->proxy_delay;
t->neigh_vars[NEIGH_VAR_LOCKTIME].data = &p->locktime;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].data = &p->retrans_time;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].data = &p->base_reachable_time;
if (dev) {
dev_name_source = dev->name;
/* Terminate the table early */
memset(&t->neigh_vars[14], 0, sizeof(t->neigh_vars[14]));
memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
} else {
dev_name_source = neigh_path[NEIGH_CTL_PATH_DEV].procname;
t->neigh_vars[14].data = (int *)(p + 1);
t->neigh_vars[15].data = (int *)(p + 1) + 1;
t->neigh_vars[16].data = (int *)(p + 1) + 2;
t->neigh_vars[17].data = (int *)(p + 1) + 3;
t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1);
t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1;
t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2;
t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = (int *)(p + 1) + 3;
}
if (handler) {
/* RetransTime */
t->neigh_vars[3].proc_handler = handler;
t->neigh_vars[3].extra1 = dev;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME].extra1 = dev;
/* ReachableTime */
t->neigh_vars[4].proc_handler = handler;
t->neigh_vars[4].extra1 = dev;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].extra1 = dev;
/* RetransTime (in milliseconds)*/
t->neigh_vars[12].proc_handler = handler;
t->neigh_vars[12].extra1 = dev;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].extra1 = dev;
/* ReachableTime (in milliseconds) */
t->neigh_vars[13].proc_handler = handler;
t->neigh_vars[13].extra1 = dev;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].extra1 = dev;
}
t->dev_name = kstrdup(dev_name_source, GFP_KERNEL);

View file

@ -107,7 +107,7 @@ struct neigh_table dn_neigh_table = {
.gc_staletime = 60 * HZ,
.reachable_time = 30 * HZ,
.delay_probe_time = 5 * HZ,
.queue_len = 3,
.queue_len_bytes = 64*1024,
.ucast_probes = 0,
.app_probes = 0,
.mcast_probes = 0,

View file

@ -177,7 +177,7 @@ struct neigh_table arp_tbl = {
.gc_staletime = 60 * HZ,
.reachable_time = 30 * HZ,
.delay_probe_time = 5 * HZ,
.queue_len = 3,
.queue_len_bytes = 64*1024,
.ucast_probes = 3,
.mcast_probes = 3,
.anycast_delay = 1 * HZ,

View file

@ -141,7 +141,7 @@ struct neigh_table nd_tbl = {
.gc_staletime = 60 * HZ,
.reachable_time = ND_REACHABLE_TIME,
.delay_probe_time = 5 * HZ,
.queue_len = 3,
.queue_len_bytes = 64*1024,
.ucast_probes = 3,
.mcast_probes = 3,
.anycast_delay = 1 * HZ,