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authorJulian Anastasov <ja@ssi.bg>2013-10-09 09:24:27 +0300
committerSimon Horman <horms@verge.net.au>2013-10-15 10:36:01 +0900
commit9e4e948a3edafd2b7f4dc14c395e146ffd0d9611 (patch)
tree2432d5bc712bc0ed0ab9f978807190d093bcd1d3 /include/net/ip_vs.h
parent120c9794a3ee2f9b1548a1b0b252652e3c134f59 (diff)
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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.h6
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)