[Devel] [PATCH hci-8.1 v3 6/6] ve: add neigh_tbl failcounter

[Vasileios Almpanis]

> Count hits of the per-VE neigh_tbl limit in ve.failcount.
> 
> This one was delayed due to a high risk of IRQ-context hits,
> when destination VE can't be obtained from get_exec_env.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-135520
> https://virtuozzo.atlassian.net/browse/VSTOR-146839
> 
> Feature: per-ve failcounters
> Feature: ve printk
> Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
>
> diff --git a/include/linux/ve.h b/include/linux/ve.h
> index 946df4eebe89..44e04dc75823 100644
> --- a/include/linux/ve.h
> +++ b/include/linux/ve.h
> @@ -97,6 +97,7 @@ struct ve_struct {
>  
>  	atomic_t		arp_neigh_nr;
>  	atomic_t		nd_neigh_nr;
> +	atomic_t		neigh_tbl_failcount;
>  	unsigned long		meminfo_val;
>  
>  	/*
> diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
> index 51cc635be2e2..35fad9658149 100644
> --- a/kernel/ve/ve.c
> +++ b/kernel/ve/ve.c
> @@ -118,6 +118,7 @@ struct ve_struct ve0 = {
>  
>  	.arp_neigh_nr		= ATOMIC_INIT(0),
>  	.nd_neigh_nr		= ATOMIC_INIT(0),
> +	.neigh_tbl_failcount	= ATOMIC_INIT(0),
>  	.mnt_avail_nr		= ATOMIC_INIT(INT_MAX),
>  	.mnt_max_nr		= INT_MAX,
>  	.mnt_failcount		= ATOMIC_INIT(0),
> @@ -834,6 +835,7 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
>  
>  	atomic_set(&ve->arp_neigh_nr, 0);
>  	atomic_set(&ve->nd_neigh_nr, 0);
> +	atomic_set(&ve->neigh_tbl_failcount, 0);
>  	ve->mnt_max_nr = MNT_MAX_NR_DEFAULT;
>  	atomic_set(&ve->mnt_failcount, 0);
>  	atomic_set(&ve->mnt_avail_nr, MNT_MAX_NR_DEFAULT);
> @@ -1098,6 +1100,7 @@ static const struct ve_failcount_entry {
>  	VE_FC_ENTRY(mnt),
>  	VE_FC_ENTRY(netif),
>  	VE_FC_ENTRY(bpf_prog),
> +	VE_FC_ENTRY(neigh_tbl),
>  #ifdef CONFIG_AIO
>  	VE_FC_ENTRY(aio),
>  #endif
> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
> index f90deb17fb25..6c2fc778a8ab 100644
> --- a/net/core/neighbour.c
> +++ b/net/core/neighbour.c
> @@ -520,8 +520,9 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl,
>  	    (glob_entries >= READ_ONCE(tbl->gc_thresh2) &&
>  	     time_after(now, READ_ONCE(tbl->last_flush) + 5 * HZ))) {
>  		if (!neigh_forced_gc(tbl, ve) && entries >= gc_thresh3) {
> -			net_info_ratelimited("%s: neighbor table overflow!\n",
> -					     tbl->id);
> +			net_info_ratelimited("%s: neighbor table overflow for ve %s!\n",
> +					     tbl->id, ve_name(ve));

Here on hosts with more neighbors than the threshold the host will get a
message which points to a failcount file it doesn't exist. Maybe only
increase failcount in case ve is not super?

-- 
Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>