[PATCH] netlink workaround silly yield()

[Clark Williams <williams@redhat.com>]

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Thomas,

Below is a patch we added to avoid deadlocks in certain RT JVM cases.
The original was authored by rostedt and was modified further by acme.
This version applies to 2.6.29.1-rt7.

Clark


Added test for rt_task(current) to avoid deadlock with
RT task calling sched_yield()

Author: Steven Rostedt <srostedt@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Clark Williams <williams@redhat.com>
- ---

 net/netlink/af_netlink.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 3ae3cb8..e8f2775 100644
- --- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1046,7 +1046,7 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
 		kfree_skb(info.skb2);
 
 	if (info.delivered) {
- -		if (info.congested && (allocation & __GFP_WAIT))
+		if (info.congested && (allocation & __GFP_WAIT) && !rt_task(current))
 			yield();
 		return 0;
 	}
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