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| author | Eric Dumazet <edumazet@google.com> | 2022-02-07 11:07:06 -0800 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2022-02-24 08:26:03 +0100 |
| commit | 181d4447905d551cc664f1e7e796b482c1eec992 (patch) | |
| tree | 28962c41f02866e4d6d0a928c9747ddb97a9d578 /net/can | |
| parent | 58212e03e5ec315b368afea5a32a87866feb59b0 (diff) | |
| download | linux-181d4447905d551cc664f1e7e796b482c1eec992.tar.bz2 | |
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.c | 16 |
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; } |