[Devel] [PATCH RHEL8 COMMIT] ve/net/neighbour: per-ct limit for neighbour entries
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Jun 9 18:21:48 MSK 2021
The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.38
------>
commit 830834d783bb5d3226d9542588e49c995e62a7ea
Author: Vasily Averin <vvs at virtuozzo.com>
Date: Wed Jun 9 18:21:48 2021 +0300
ve/net/neighbour: per-ct limit for neighbour entries
Based on patch from Konstantin Khoerenko <khorenko at virtuozzo.com>
Currently neighours do not have per-namespace structures and use
common hash, locks, counters and global limits.
Total number of neigh entries on a Node can easily exceed the
global gc_thresh3 on the Node. (We've got an Node with 67 active
Containers which required ~6000 active neighbour entries).
Let's introduce additional counters for neigh entries per Container and
check max limit against them. Global counters for neigh entries are left
as is, they will be used for periodical and forced cleanups as it works
now.
https://jira.sw.ru/browse/PSBM-87155
Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
Acked-by: Konstantin Khorenko <khorenko at virtuozzo.com>
(cherry picked from vz7 commit c75e42c15e7d ("ve/net/neighbour: per-ct limit for
neighbour entries"))
VZ 8 rebase part https://jira.sw.ru/browse/PSBM-127837
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
---
include/linux/ve.h | 2 ++
kernel/ve/ve.c | 4 ++++
net/core/neighbour.c | 42 ++++++++++++++++++++++++++++++++++++------
3 files changed, 42 insertions(+), 6 deletions(-)
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 7d6837fef8c6..7fb28fa8dce8 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -82,6 +82,8 @@ struct ve_struct {
struct kthread_worker umh_worker;
struct task_struct *umh_task;
+ atomic_t arp_neigh_nr;
+ atomic_t nd_neigh_nr;
unsigned long meminfo_val;
atomic_t mnt_nr; /* number of present VE mounts */
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index a04cdd5fe1f2..3e0ee4cc3775 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -75,6 +75,8 @@ struct ve_struct ve0 = {
#else
2,
#endif
+ .arp_neigh_nr = ATOMIC_INIT(0),
+ .nd_neigh_nr = ATOMIC_INIT(0),
.mnt_nr = ATOMIC_INIT(0),
.netns_avail_nr = ATOMIC_INIT(INT_MAX),
.netns_max_nr = INT_MAX,
@@ -942,6 +944,8 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
INIT_LIST_HEAD(&ve->ve_list);
kmapset_init_key(&ve->sysfs_perms_key);
+ atomic_set(&ve->arp_neigh_nr, 0);
+ atomic_set(&ve->nd_neigh_nr, 0);
atomic_set(&ve->mnt_nr, 0);
#ifdef CONFIG_COREDUMP
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 12cdfb182508..bdd985310bc3 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -166,7 +166,7 @@ bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl)
return false;
}
-static int neigh_forced_gc(struct neigh_table *tbl)
+static int neigh_forced_gc(struct neigh_table *tbl, struct ve_struct *ve)
{
int shrunk = 0;
int i;
@@ -184,13 +184,15 @@ static int neigh_forced_gc(struct neigh_table *tbl)
np = &nht->hash_buckets[i];
while ((n = rcu_dereference_protected(*np,
lockdep_is_held(&tbl->lock))) != NULL) {
+ bool same_ve = (dev_net(n->dev)->owner_ve == ve);
/* Neighbour record may be discarded if:
* - nobody refers to it.
* - it is not permanent
*/
if (neigh_del(n, NUD_PERMANENT, NTF_EXT_LEARNED, np,
tbl)) {
- shrunk = 1;
+ if (same_ve)
+ shrunk = 1;
continue;
}
np = &n->next;
@@ -323,17 +325,39 @@ int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
}
EXPORT_SYMBOL(neigh_ifdown);
+static inline atomic_t *get_perve_tbl_entries_counter(struct neigh_table *tbl,
+ struct ve_struct *ve)
+{
+ switch (tbl->family) {
+ case AF_INET:
+ return &ve->arp_neigh_nr;
+ case AF_INET6:
+ return &ve->nd_neigh_nr;
+ }
+ return NULL;
+}
+
static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device *dev)
{
struct neighbour *n = NULL;
unsigned long now = jiffies;
- int entries;
+ int entries, glob_entries;
+ atomic_t *cnt;
+ struct ve_struct *ve = dev_net(dev)->owner_ve;
+
+ /* If per-VE counter of neighbour entries exist
+ * it will be limited by tbl->gc_thresh3
+ * and according global counter (tbl->entries) become unlimited.
+ */
+
+ glob_entries = atomic_inc_return(&tbl->entries) - 1;
+ cnt = get_perve_tbl_entries_counter(tbl, ve);
+ entries = cnt ? atomic_inc_return(cnt) - 1 : glob_entries;
- entries = atomic_inc_return(&tbl->entries) - 1;
if (entries >= tbl->gc_thresh3 ||
- (entries >= tbl->gc_thresh2 &&
+ (glob_entries >= tbl->gc_thresh2 &&
time_after(now, tbl->last_flush + 5 * HZ))) {
- if (!neigh_forced_gc(tbl) &&
+ if (!neigh_forced_gc(tbl, ve) &&
entries >= tbl->gc_thresh3) {
net_info_ratelimited("%s: neighbor table overflow!\n",
tbl->id);
@@ -365,6 +389,8 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device
out_entries:
atomic_dec(&tbl->entries);
+ if (cnt)
+ atomic_dec(cnt);
goto out;
}
@@ -751,6 +777,8 @@ static inline void neigh_parms_put(struct neigh_parms *parms)
void neigh_destroy(struct neighbour *neigh)
{
struct net_device *dev = neigh->dev;
+ struct ve_struct *ve = dev_net(dev)->owner_ve;
+ atomic_t *cnt = get_perve_tbl_entries_counter(neigh->tbl, ve);
NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
@@ -776,6 +804,8 @@ void neigh_destroy(struct neighbour *neigh)
neigh_dbg(2, "neigh %p is destroyed\n", neigh);
+ if (cnt)
+ atomic_dec(cnt);
atomic_dec(&neigh->tbl->entries);
kfree_rcu(neigh, rcu);
}
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