diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2022-02-12 02:38:37 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-02-14 16:38:35 +0300 |
| commit | f234ae2947612825686b25cae3e9579188a6ba95 (patch) | |
| tree | d08288408e500e2b5b4bf75c349697329bc4cd01 /net/core | |
| parent | 88f62aea1cff0c2ff84901dc11ceddf1eaf7021d (diff) | |
| download | linux-f234ae2947612825686b25cae3e9579188a6ba95.tar.xz | |
net: dev: Remove preempt_disable() and get_cpu() in netif_rx_internal().
The preempt_disable() () section was introduced in commit
cece1945bffcf ("net: disable preemption before call smp_processor_id()")
and adds it in case this function is invoked from preemtible context and
because get_cpu() later on as been added.
The get_cpu() usage was added in commit
b0e28f1effd1d ("net: netif_rx() must disable preemption")
because ip_dev_loopback_xmit() invoked netif_rx() with enabled preemption
causing a warning in smp_processor_id(). The function netif_rx() should
only be invoked from an interrupt context which implies disabled
preemption. The commit
e30b38c298b55 ("ip: Fix ip_dev_loopback_xmit()")
was addressing this and replaced netif_rx() with in netif_rx_ni() in
ip_dev_loopback_xmit().
Based on the discussion on the list, the former patch (b0e28f1effd1d)
should not have been applied only the latter (e30b38c298b55).
Remove get_cpu() and preempt_disable() since the function is supposed to
be invoked from context with stable per-CPU pointers. Bottom halves have
to be disabled at this point because the function may raise softirqs
which need to be processed.
Link: https://lkml.kernel.org/r/20100415.013347.98375530.davem@davemloft.net
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 2c3b8744e00c..441bacf79199 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4796,7 +4796,6 @@ static int netif_rx_internal(struct sk_buff *skb) struct rps_dev_flow voidflow, *rflow = &voidflow; int cpu; - preempt_disable(); rcu_read_lock(); cpu = get_rps_cpu(skb->dev, skb, &rflow); @@ -4806,14 +4805,12 @@ static int netif_rx_internal(struct sk_buff *skb) ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); rcu_read_unlock(); - preempt_enable(); } else #endif { unsigned int qtail; - ret = enqueue_to_backlog(skb, get_cpu(), &qtail); - put_cpu(); + ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail); } return ret; } |