[Devel] [PATCH hci-8.1 v2 6/6] ve: add neigh_tbl failcounter

[Vladimir Riabchun]

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>
---
 include/linux/ve.h   | 1 +
 kernel/ve/ve.c       | 3 +++
 net/core/neighbour.c | 5 +++--
 3 files changed, 7 insertions(+), 2 deletions(-)

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));
+			ve_failcount_inc(ve, neigh_tbl);
 			NEIGH_CACHE_STAT_INC(tbl, table_fulls);
 			goto out_entries;
 		}

-- 
2.52.0