* [memnic PATCH] linux: fix to disable softirq before netif_receive_skb()
@ 2014-06-06 7:54 Hiroshi Shimamoto
[not found] ` <7F861DC0615E0C47A872E6F3C5FCDDBD01101844-ZmjkEB1lVlLt6d3pZDjeaEtBU8KWyXPq@public.gmane.org>
0 siblings, 1 reply; 2+ messages in thread
From: Hiroshi Shimamoto @ 2014-06-06 7:54 UTC (permalink / raw)
To: dev-VfR2kkLFssw@public.gmane.org; +Cc: Hayato Momma
From: Hiroshi Shimamoto <h-shimamoto-ehU+Cx/zZe18UrSeD/g0lQ@public.gmane.org>
Calling netif_receive_skb() from memnic thread may cause deadlock, if
softirq is not disabled.
The netif_receive_skb() should be called in softirq context, but memnic
thread is not softirq context. That may conflict softirq work like a
timer handler in kernel network stack.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto-ehU+Cx/zZe18UrSeD/g0lQ@public.gmane.org>
Reviewed-by: Hayato Momma <h-momma-JhyGz2TFV9J8UrSeD/g0lQ@public.gmane.org>
---
linux/memnic_net.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/linux/memnic_net.c b/linux/memnic_net.c
index fadece6..a1b433a 100644
--- a/linux/memnic_net.c
+++ b/linux/memnic_net.c
@@ -133,8 +133,14 @@ static int memnic_thread(void *param)
continue;
}
+ local_bh_disable();
+ /*
+ * Disable softirq here to avoid race between timers and
+ * netif_receive_skb
+ */
for (i = 0; i < n; i++)
netif_receive_skb(skbs[i]);
+ local_bh_enable();
cnt = 0;
}
--
1.8.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [memnic PATCH] linux: fix to disable softirq before netif_receive_skb()
[not found] ` <7F861DC0615E0C47A872E6F3C5FCDDBD01101844-ZmjkEB1lVlLt6d3pZDjeaEtBU8KWyXPq@public.gmane.org>
@ 2014-06-29 22:14 ` Thomas Monjalon
0 siblings, 0 replies; 2+ messages in thread
From: Thomas Monjalon @ 2014-06-29 22:14 UTC (permalink / raw)
To: Hiroshi Shimamoto; +Cc: dev-VfR2kkLFssw, Hayato Momma
> Calling netif_receive_skb() from memnic thread may cause deadlock, if
> softirq is not disabled.
>
> The netif_receive_skb() should be called in softirq context, but memnic
> thread is not softirq context. That may conflict softirq work like a
> timer handler in kernel network stack.
>
> Signed-off-by: Hiroshi Shimamoto <h-shimamoto-ehU+Cx/zZe18UrSeD/g0lQ@public.gmane.org>
> Reviewed-by: Hayato Momma <h-momma-JhyGz2TFV9J8UrSeD/g0lQ@public.gmane.org>
Applied
Thanks
--
Thomas
^ permalink raw reply [flat|nested] 2+ messages in thread
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2014-06-06 7:54 [memnic PATCH] linux: fix to disable softirq before netif_receive_skb() Hiroshi Shimamoto
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2014-06-29 22:14 ` Thomas Monjalon
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