diff options
| author | Julian Anastasov <ja@ssi.bg> | 2013-10-09 09:24:27 +0300 |
|---|---|---|
| committer | Simon Horman <horms@verge.net.au> | 2013-10-15 10:36:01 +0900 |
| commit | 9e4e948a3edafd2b7f4dc14c395e146ffd0d9611 (patch) | |
| tree | 2432d5bc712bc0ed0ab9f978807190d093bcd1d3 /include/net/ip_vs.h | |
| parent | 120c9794a3ee2f9b1548a1b0b252652e3c134f59 (diff) | |
| download | linux-9e4e948a3edafd2b7f4dc14c395e146ffd0d9611.tar.bz2 | |
ipvs: avoid rcu_barrier during netns cleanup
commit 578bc3ef1e473a ("ipvs: reorganize dest trash") added
rcu_barrier() on cleanup to wait dest users and schedulers
like LBLC and LBLCR to put their last dest reference.
Using rcu_barrier with many namespaces is problematic.
Trying to fix it by freeing dest with kfree_rcu is not
a solution, RCU callbacks can run in parallel and execution
order is random.
Fix it by creating new function ip_vs_dest_put_and_free()
which is heavier than ip_vs_dest_put(). We will use it just
for schedulers like LBLC, LBLCR that can delay their dest
release.
By default, dests reference is above 0 if they are present in
service and it is 0 when deleted but still in trash list.
Change the dest trash code to use ip_vs_dest_put_and_free(),
so that refcnt -1 can be used for freeing. As result,
such checks remain in slow path and the rcu_barrier() from
netns cleanup can be removed.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'include/net/ip_vs.h')
| -rw-r--r-- | include/net/ip_vs.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 1c2e1b9f6b86..cd7275f9c463 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -1442,6 +1442,12 @@ static inline void ip_vs_dest_put(struct ip_vs_dest *dest) atomic_dec(&dest->refcnt); } +static inline void ip_vs_dest_put_and_free(struct ip_vs_dest *dest) +{ + if (atomic_dec_return(&dest->refcnt) < 0) + kfree(dest); +} + /* * IPVS sync daemon data and function prototypes * (from ip_vs_sync.c) |