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authorEric Dumazet <edumazet@google.com>2022-02-07 22:07:06 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2022-02-24 10:26:03 +0300
commit181d4447905d551cc664f1e7e796b482c1eec992 (patch)
tree28962c41f02866e4d6d0a928c9747ddb97a9d578 /net/can
parent58212e03e5ec315b368afea5a32a87866feb59b0 (diff)
downloadlinux-181d4447905d551cc664f1e7e796b482c1eec992.tar.xz
can: gw: use call_rcu() instead of costly synchronize_rcu()
Commit fb8696ab14ad ("can: gw: synchronize rcu operations before removing gw job entry") added three synchronize_rcu() calls to make sure one rcu grace period was observed before freeing a "struct cgw_job" (which are tiny objects). This should be converted to call_rcu() to avoid adding delays in device / network dismantles. Use the rcu_head that was already in struct cgw_job, not yet used. Link: https://lore.kernel.org/all/20220207190706.1499190-1-eric.dumazet@gmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Oliver Hartkopp <socketcan@hartkopp.net> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/gw.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/net/can/gw.c b/net/can/gw.c
index 24221352e059..1ea4cc527db3 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -577,6 +577,13 @@ static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
}
+static void cgw_job_free_rcu(struct rcu_head *rcu_head)
+{
+ struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu);
+
+ kmem_cache_free(cgw_cache, gwj);
+}
+
static int cgw_notifier(struct notifier_block *nb,
unsigned long msg, void *ptr)
{
@@ -596,8 +603,7 @@ static int cgw_notifier(struct notifier_block *nb,
if (gwj->src.dev == dev || gwj->dst.dev == dev) {
hlist_del(&gwj->list);
cgw_unregister_filter(net, gwj);
- synchronize_rcu();
- kmem_cache_free(cgw_cache, gwj);
+ call_rcu(&gwj->rcu, cgw_job_free_rcu);
}
}
}
@@ -1155,8 +1161,7 @@ static void cgw_remove_all_jobs(struct net *net)
hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
hlist_del(&gwj->list);
cgw_unregister_filter(net, gwj);
- synchronize_rcu();
- kmem_cache_free(cgw_cache, gwj);
+ call_rcu(&gwj->rcu, cgw_job_free_rcu);
}
}
@@ -1224,8 +1229,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
hlist_del(&gwj->list);
cgw_unregister_filter(net, gwj);
- synchronize_rcu();
- kmem_cache_free(cgw_cache, gwj);
+ call_rcu(&gwj->rcu, cgw_job_free_rcu);
err = 0;
break;
}